diff --git a/data/src/main/kotlin/io/zeebe/zeeqs/data/entity/BpmnElementType.kt b/data/src/main/kotlin/io/zeebe/zeeqs/data/entity/BpmnElementType.kt
index 570be2e6..08ba6586 100644
--- a/data/src/main/kotlin/io/zeebe/zeeqs/data/entity/BpmnElementType.kt
+++ b/data/src/main/kotlin/io/zeebe/zeeqs/data/entity/BpmnElementType.kt
@@ -25,5 +25,6 @@ enum class BpmnElementType {
     BUSINESS_RULE_TASK,
     SCRIPT_TASK,
     SEND_TASK,
-    INCLUSIVE_GATEWAY
+    INCLUSIVE_GATEWAY,
+    GROUP
 }
diff --git a/data/src/main/kotlin/io/zeebe/zeeqs/data/entity/VariableFilter.kt b/data/src/main/kotlin/io/zeebe/zeeqs/data/entity/VariableFilter.kt
new file mode 100644
index 00000000..4cfee606
--- /dev/null
+++ b/data/src/main/kotlin/io/zeebe/zeeqs/data/entity/VariableFilter.kt
@@ -0,0 +1,22 @@
+package io.zeebe.zeeqs.data.entity
+
+enum class ComparisonOperation {
+    EQUALS,
+    CONTAINS
+}
+
+enum class FilterOperation {
+    AND,
+    OR
+}
+
+class VariableFilter (
+        val name: String,
+        val value: String,
+        val comparisonOperation: ComparisonOperation = ComparisonOperation.EQUALS
+)
+
+class VariableFilterGroup (
+        val variables: List<VariableFilter>,
+        val filterOperation: FilterOperation = FilterOperation.OR
+)
\ No newline at end of file
diff --git a/data/src/main/kotlin/io/zeebe/zeeqs/data/repository/ProcessInstanceRepository.kt b/data/src/main/kotlin/io/zeebe/zeeqs/data/repository/ProcessInstanceRepository.kt
index f9bcff71..95959bbc 100644
--- a/data/src/main/kotlin/io/zeebe/zeeqs/data/repository/ProcessInstanceRepository.kt
+++ b/data/src/main/kotlin/io/zeebe/zeeqs/data/repository/ProcessInstanceRepository.kt
@@ -6,17 +6,26 @@ import org.springframework.data.domain.Pageable
 import org.springframework.data.repository.PagingAndSortingRepository
 import org.springframework.stereotype.Repository
 
+interface ProcessInstanceKeyOnly {
+    fun getKey(): Long
+}
+
 @Repository
 interface ProcessInstanceRepository : PagingAndSortingRepository<ProcessInstance, Long> {
 
     fun findByParentProcessInstanceKey(parentProcessInstanceKey: Long): List<ProcessInstance>
 
+    fun findByProcessDefinitionKeyAndStateIn(processDefinitionKey: Long, stateIn: List<ProcessInstanceState>): List<ProcessInstanceKeyOnly>
+
     fun findByProcessDefinitionKeyAndStateIn(processDefinitionKey: Long, stateIn: List<ProcessInstanceState>, pageable: Pageable): List<ProcessInstance>
 
     fun countByProcessDefinitionKeyAndStateIn(processDefinitionKey: Long, stateIn: List<ProcessInstanceState>): Long
 
     fun findByStateIn(stateIn: List<ProcessInstanceState>, pageable: Pageable): List<ProcessInstance>
 
+    fun findByStateIn(stateIn: List<ProcessInstanceState>): List<ProcessInstanceKeyOnly>
+
     fun countByStateIn(stateIn: List<ProcessInstanceState>): Long
 
+    fun findByStateInAndKeyIn(stateIn: List<ProcessInstanceState>, key: List<Long>, pageable: Pageable): List<ProcessInstance>
 }
\ No newline at end of file
diff --git a/data/src/main/kotlin/io/zeebe/zeeqs/data/repository/VariableRepository.kt b/data/src/main/kotlin/io/zeebe/zeeqs/data/repository/VariableRepository.kt
index 5f9a315e..54107210 100644
--- a/data/src/main/kotlin/io/zeebe/zeeqs/data/repository/VariableRepository.kt
+++ b/data/src/main/kotlin/io/zeebe/zeeqs/data/repository/VariableRepository.kt
@@ -13,4 +13,12 @@ interface VariableRepository : PagingAndSortingRepository<Variable, Long> {
 
     @Transactional(readOnly = true)
     fun findByScopeKey(scopeKey: Long): List<Variable>
+
+    @Transactional(readOnly = true)
+    fun findByProcessInstanceKeyInAndName(processInstanceKey: List<Long>, name: String): List<Variable>
+
+
+    @Transactional(readOnly = true)
+    fun findByProcessInstanceKeyInAndNameIn(processInstanceKey: List<Long>, name: List<String>): List<Variable>
+
 }
\ No newline at end of file
diff --git a/data/src/main/kotlin/io/zeebe/zeeqs/data/service/BpmnElementInfo.kt b/data/src/main/kotlin/io/zeebe/zeeqs/data/service/BpmnElementInfo.kt
index f3d786ea..1271be1f 100644
--- a/data/src/main/kotlin/io/zeebe/zeeqs/data/service/BpmnElementInfo.kt
+++ b/data/src/main/kotlin/io/zeebe/zeeqs/data/service/BpmnElementInfo.kt
@@ -6,5 +6,7 @@ data class BpmnElementInfo(
         val elementId: String,
         val elementName: String?,
         val elementType: BpmnElementType,
-        val metadata: BpmnElementMetadata
+        val metadata: BpmnElementMetadata,
+        val extensionElements: BpmnExtensionElements?,
+        val documentation: String?
 )
\ No newline at end of file
diff --git a/data/src/main/kotlin/io/zeebe/zeeqs/data/service/BpmnExtensionElements.kt b/data/src/main/kotlin/io/zeebe/zeeqs/data/service/BpmnExtensionElements.kt
new file mode 100644
index 00000000..e216551a
--- /dev/null
+++ b/data/src/main/kotlin/io/zeebe/zeeqs/data/service/BpmnExtensionElements.kt
@@ -0,0 +1,20 @@
+package io.zeebe.zeeqs.data.service
+
+data class BpmnExtensionProperty(
+        val name: String?,
+        val value: String?
+)
+
+data class IoMapping (
+        val source: String?,
+        val target: String?
+)
+data class ExtensionIoMapping(
+        val inputs: List<IoMapping>? = emptyList(),
+        val outputs: List<IoMapping>? = emptyList(),
+)
+data class BpmnExtensionElements(
+        val properties: List<BpmnExtensionProperty>? = emptyList(),
+        val ioMapping: ExtensionIoMapping? = ExtensionIoMapping(),
+)
+
diff --git a/data/src/main/kotlin/io/zeebe/zeeqs/data/service/ProcessInstanceService.kt b/data/src/main/kotlin/io/zeebe/zeeqs/data/service/ProcessInstanceService.kt
new file mode 100644
index 00000000..a8d24311
--- /dev/null
+++ b/data/src/main/kotlin/io/zeebe/zeeqs/data/service/ProcessInstanceService.kt
@@ -0,0 +1,93 @@
+package io.zeebe.zeeqs.data.service
+
+import io.zeebe.zeeqs.data.entity.*
+import io.zeebe.zeeqs.data.repository.ProcessInstanceKeyOnly
+import io.zeebe.zeeqs.data.repository.ProcessInstanceRepository
+import io.zeebe.zeeqs.data.repository.VariableRepository
+import org.springframework.data.domain.PageRequest
+import org.springframework.stereotype.Component
+
+@Component
+class ProcessInstanceService(
+        private val processInstancesRepository: ProcessInstanceRepository,
+        private val variableRepository: VariableRepository) {
+
+    private fun getVariables(stateIn: List<ProcessInstanceState>, variableFilterGroup: VariableFilterGroup): List<Variable> {
+        val processInstances = processInstancesRepository.findByStateIn(stateIn).toList();
+        return getVariablesByProcessInstanceKeys(processInstances, variableFilterGroup);
+    }
+
+    private fun getVariables(stateIn: List<ProcessInstanceState>, processDefinitionKey: Long, variableFilterGroup: VariableFilterGroup): List<Variable> {
+        val processInstances = processInstancesRepository.findByProcessDefinitionKeyAndStateIn(processDefinitionKey, stateIn).toList();
+        return getVariablesByProcessInstanceKeys(processInstances, variableFilterGroup);
+
+    }
+
+    private fun matchesFilter(variable: Variable, filter: VariableFilter): Boolean {
+        return when (filter.comparisonOperation) {
+            ComparisonOperation.EQUALS -> variable.name == filter.name && variable.value == filter.value
+            ComparisonOperation.CONTAINS -> variable.name == filter.name && variable.value.contains(filter.value)
+        }
+    }
+
+    private fun getVariablesByProcessInstanceKeys(processInstances: List<ProcessInstanceKeyOnly>, variableFilterGroup: VariableFilterGroup): List<Variable> {
+        val processInstancesKeys = processInstances.map { it.getKey() }
+        val variableNames = variableFilterGroup.variables.map { it.name }
+        val variablesList = variableRepository.findByProcessInstanceKeyInAndNameIn(processInstancesKeys, variableNames)
+
+        return variablesList.filter { variable ->
+            if (variableFilterGroup.filterOperation == FilterOperation.AND) {
+                variableFilterGroup.variables.all { matchesFilter(variable, it) }
+            } else {
+                variableFilterGroup.variables.any { matchesFilter(variable, it) }
+            }
+        }
+    }
+
+
+    fun getProcessInstances(perPage: Int, page: Int, stateIn: List<ProcessInstanceState>, variableFilterGroup: VariableFilterGroup?): List<ProcessInstance> {
+        if (variableFilterGroup?.variables?.isNotEmpty() == true) {
+            val filteredVariables = getVariables(stateIn, variableFilterGroup);
+            val filteredProcessInstances = processInstancesRepository.findByStateInAndKeyIn(stateIn, filteredVariables.map { it.processInstanceKey }, PageRequest.of(page, perPage)).toList();
+            return filteredProcessInstances;
+        }
+        else {
+            return processInstancesRepository.findByStateIn(stateIn, PageRequest.of(page, perPage)).toList();
+        }
+    }
+
+    fun countProcessInstances(stateIn: List<ProcessInstanceState>, variableFilterGroup: VariableFilterGroup?): Long {
+        if (variableFilterGroup?.variables?.isNotEmpty() == true) {
+            val filteredVariables = getVariables(stateIn, variableFilterGroup);
+            return filteredVariables.count().toLong();
+        }
+
+        else {
+            return processInstancesRepository.countByStateIn(stateIn);
+        }
+    }
+
+
+    fun getProcessInstances(perPage: Int, page: Int, stateIn: List<ProcessInstanceState>, processDefinitionKey: Long, variableFilterGroup: VariableFilterGroup?): List<ProcessInstance> {
+        if (variableFilterGroup?.variables?.isNotEmpty() == true) {
+            val filteredVariables = getVariables(stateIn, processDefinitionKey, variableFilterGroup);
+            val filteredProcessInstances = processInstancesRepository.findByStateInAndKeyIn(stateIn, filteredVariables.map { it.processInstanceKey }, PageRequest.of(page, perPage)).toList();
+            return filteredProcessInstances;
+        }
+        else {
+            return processInstancesRepository.findByProcessDefinitionKeyAndStateIn(processDefinitionKey, stateIn, PageRequest.of(page, perPage)).toList();
+        }
+    }
+
+    fun countProcessInstances(stateIn: List<ProcessInstanceState>, processDefinitionKey: Long, variableFilterGroup: VariableFilterGroup?): Long {
+        if (variableFilterGroup?.variables?.isNotEmpty() == true) {
+            val filteredVariables = getVariables(stateIn, processDefinitionKey, variableFilterGroup);
+            return filteredVariables.count().toLong();
+        }
+
+        else {
+            return processInstancesRepository.countByProcessDefinitionKeyAndStateIn(processDefinitionKey, stateIn);
+        }
+    }
+
+}
\ No newline at end of file
diff --git a/data/src/main/kotlin/io/zeebe/zeeqs/data/service/ProcessService.kt b/data/src/main/kotlin/io/zeebe/zeeqs/data/service/ProcessService.kt
index 794a692f..49a2272c 100644
--- a/data/src/main/kotlin/io/zeebe/zeeqs/data/service/ProcessService.kt
+++ b/data/src/main/kotlin/io/zeebe/zeeqs/data/service/ProcessService.kt
@@ -20,18 +20,28 @@ class ProcessService(val processRepository: ProcessRepository) {
     @Cacheable(cacheNames = ["bpmnElementInfo"])
     fun getBpmnElementInfo(processDefinitionKey: Long): Map<String, BpmnElementInfo>? {
         return getBpmnModel(processDefinitionKey)
-            ?.let { it.getModelElementsByType(FlowElement::class.java) }
-            ?.map { flowElement ->
-                Pair(
-                    flowElement.id, BpmnElementInfo(
-                        elementId = flowElement.id,
-                        elementName = flowElement.name,
-                        elementType = getBpmnElementType(flowElement),
-                        metadata = getMetadata(flowElement)
-                    )
-                )
-            }
-            ?.toMap()
+                ?.let { model ->
+                    (model.getModelElementsByType(FlowElement::class.java)?.associate { flowElement ->
+                        flowElement.id to BpmnElementInfo(
+                                elementId = flowElement.id,
+                                elementName = flowElement.name,
+                                elementType = getBpmnElementType(flowElement),
+                                metadata = getMetadata(flowElement),
+                                extensionElements = getExtensionElements(flowElement),
+                                documentation = getDocumentation(flowElement)
+                        )
+                    }.orEmpty() +
+                            model.getModelElementsByType(Group::class.java)?.associate { groupElement ->
+                                groupElement.id to BpmnElementInfo(
+                                        elementId = groupElement.id,
+                                        elementName = groupElement.category?.value ?: "",
+                                        elementType = getBpmnElementType(groupElement),
+                                        metadata = getMetadata(groupElement),
+                                        extensionElements = getExtensionElements(groupElement),
+                                        documentation = getDocumentation(groupElement)
+                                )
+                            }.orEmpty())
+                }
     }
 
     private fun getBpmnModel(processDefinitionKey: Long): BpmnModelInstance? {
@@ -41,7 +51,7 @@ class ProcessService(val processRepository: ProcessRepository) {
             ?.let { Bpmn.readModelFromStream(it) }
     }
 
-    private fun getBpmnElementType(element: FlowElement): BpmnElementType {
+    private fun getBpmnElementType(element: BaseElement): BpmnElementType {
         return when (element.elementType.typeName) {
             BpmnModelConstants.BPMN_ELEMENT_PROCESS -> BpmnElementType.PROCESS
             BpmnModelConstants.BPMN_ELEMENT_SUB_PROCESS -> getBpmnSubprocessType(element)
@@ -63,11 +73,12 @@ class ProcessService(val processRepository: ProcessRepository) {
             BpmnModelConstants.BPMN_ELEMENT_BUSINESS_RULE_TASK -> BpmnElementType.BUSINESS_RULE_TASK
             BpmnModelConstants.BPMN_ELEMENT_SCRIPT_TASK -> BpmnElementType.SCRIPT_TASK
             BpmnModelConstants.BPMN_ELEMENT_INCLUSIVE_GATEWAY -> BpmnElementType.INCLUSIVE_GATEWAY
+            BpmnModelConstants.BPMN_ELEMENT_GROUP -> BpmnElementType.GROUP
             else -> BpmnElementType.UNKNOWN
         }
     }
 
-    private fun getBpmnSubprocessType(element: FlowElement) =
+    private fun getBpmnSubprocessType(element: BaseElement) =
         if (element is SubProcess) {
             if (element.triggeredByEvent()) {
                 BpmnElementType.EVENT_SUB_PROCESS
@@ -78,7 +89,7 @@ class ProcessService(val processRepository: ProcessRepository) {
             BpmnElementType.UNKNOWN
         }
 
-    private fun getMetadata(element: FlowElement): BpmnElementMetadata {
+    private fun getMetadata(element: BaseElement): BpmnElementMetadata {
         return BpmnElementMetadata(
             jobType = element
                 .getSingleExtensionElement(ZeebeTaskDefinition::class.java)
@@ -156,6 +167,41 @@ class ProcessService(val processRepository: ProcessRepository) {
         )
     }
 
+    private fun getExtensionElements(element: BaseElement): BpmnExtensionElements {
+
+        val properties = element.extensionElements?.elementsQuery
+                ?.filterByType(ZeebeProperties::class.java)
+                ?.findSingleResult()
+                ?.map { properties ->
+                    properties.properties?.map { property ->
+                        BpmnExtensionProperty(name = property.name, value = property.value)
+                    }
+                }
+                ?.orElse(emptyList()) ?: emptyList()
+
+        val ioMapping = element.extensionElements?.elementsQuery
+                ?.filterByType(ZeebeIoMapping::class.java)
+                ?.findSingleResult()
+                ?.map { mapping ->
+                    ExtensionIoMapping(
+                            inputs = mapping.inputs?.map { input ->
+                                IoMapping(source = input.source, target = input.target)
+                            } ?: emptyList(),
+                            outputs = mapping.outputs?.map { output ->
+                                IoMapping(source = output.source, target = output.target)
+                            } ?: emptyList()
+                    )
+                }
+                ?.orElse(ExtensionIoMapping(inputs = emptyList(), outputs = emptyList())) ?: ExtensionIoMapping(inputs = emptyList(), outputs = emptyList())
+
+        return BpmnExtensionElements(properties = properties, ioMapping = ioMapping)
+    }
+
+
+    private fun getDocumentation(element: BaseElement): String {
+        return element.documentations.joinToString(separator = "") { it.textContent }
+    }
+
     @Cacheable(cacheNames = ["userTaskForm"])
     fun getForm(processDefinitionKey: Long, formKey: String): String? {
         return getBpmnModel(processDefinitionKey)
diff --git a/data/src/test/kotlin/io/zeebe/zeeqs/ProcessServiceTest.kt b/data/src/test/kotlin/io/zeebe/zeeqs/ProcessServiceTest.kt
index 337243b1..c6e0d7ee 100644
--- a/data/src/test/kotlin/io/zeebe/zeeqs/ProcessServiceTest.kt
+++ b/data/src/test/kotlin/io/zeebe/zeeqs/ProcessServiceTest.kt
@@ -12,7 +12,6 @@ import org.junit.jupiter.api.BeforeEach
 import org.junit.jupiter.api.Nested
 import org.junit.jupiter.api.Test
 import org.springframework.beans.factory.annotation.Autowired
-import org.springframework.boot.autoconfigure.SpringBootApplication
 import org.springframework.boot.test.context.SpringBootTest
 import org.springframework.boot.test.context.TestConfiguration
 import java.time.Instant
@@ -52,12 +51,12 @@ class ProcessServiceTest(
             // then
             assertThat(info)
                     .isNotNull()
-                    .contains(entry("s", BpmnElementInfo("s", "start", BpmnElementType.START_EVENT, BpmnElementMetadata())))
-                    .contains(entry("t", BpmnElementInfo("t", "task", BpmnElementType.SERVICE_TASK, BpmnElementMetadata(jobType = "test"))))
+                    .contains(entry("s", BpmnElementInfo("s", "start", BpmnElementType.START_EVENT, BpmnElementMetadata(), BpmnExtensionElements(properties = emptyList(), ioMapping = ExtensionIoMapping()), "")))
+                    .contains(entry("t", BpmnElementInfo("t", "task", BpmnElementType.SERVICE_TASK, BpmnElementMetadata(jobType = "test"), BpmnExtensionElements(properties = emptyList(), ioMapping = ExtensionIoMapping()), "")))
                     .contains(entry("u", BpmnElementInfo("u", "userTask", BpmnElementType.USER_TASK, BpmnElementMetadata(
-                            userTaskAssignmentDefinition = UserTaskAssignmentDefinition(assignee = "user1", candidateGroups = "group1"))))
+                            userTaskAssignmentDefinition = UserTaskAssignmentDefinition(assignee = "user1", candidateGroups = "group1")), BpmnExtensionElements(properties = emptyList(), ioMapping = ExtensionIoMapping()), ""))
                     )
-                    .contains(entry("e", BpmnElementInfo("e", null, BpmnElementType.END_EVENT, BpmnElementMetadata())))
+                    .contains(entry("e", BpmnElementInfo("e", null, BpmnElementType.END_EVENT, BpmnElementMetadata(), BpmnExtensionElements(properties = emptyList(), ioMapping = ExtensionIoMapping()), "")))
         }
 
         @Test
@@ -90,7 +89,9 @@ class ProcessServiceTest(
                                                     key = "camunda-forms:bpmn:form_A",
                                                     resource = """{"x":1}"""
                                             )
-                                    )
+                                    ),
+                                    BpmnExtensionElements(properties = emptyList(), ioMapping = ExtensionIoMapping()),
+                                    ""
                             )
                     )
         }
diff --git a/graphql-api/src/main/kotlin/io/zeebe/zeeqs/graphql/resolvers/query/ProcessInstanceQueryResolver.kt b/graphql-api/src/main/kotlin/io/zeebe/zeeqs/graphql/resolvers/query/ProcessInstanceQueryResolver.kt
index 7943c905..10679efc 100644
--- a/graphql-api/src/main/kotlin/io/zeebe/zeeqs/graphql/resolvers/query/ProcessInstanceQueryResolver.kt
+++ b/graphql-api/src/main/kotlin/io/zeebe/zeeqs/graphql/resolvers/query/ProcessInstanceQueryResolver.kt
@@ -2,7 +2,9 @@ package io.zeebe.zeeqs.graphql.resolvers.query
 
 import io.zeebe.zeeqs.data.entity.ProcessInstance
 import io.zeebe.zeeqs.data.entity.ProcessInstanceState
+import io.zeebe.zeeqs.data.entity.VariableFilterGroup
 import io.zeebe.zeeqs.data.repository.ProcessInstanceRepository
+import io.zeebe.zeeqs.data.service.ProcessInstanceService
 import io.zeebe.zeeqs.graphql.resolvers.connection.ProcessInstanceConnection
 import org.springframework.data.domain.PageRequest
 import org.springframework.data.repository.findByIdOrNull
@@ -12,18 +14,20 @@ import org.springframework.stereotype.Controller
 
 @Controller
 class ProcessInstanceQueryResolver(
-        val processInstanceRepository: ProcessInstanceRepository
+        val processInstanceRepository: ProcessInstanceRepository,
+        val processInstanceService: ProcessInstanceService
 ) {
 
     @QueryMapping
     fun processInstances(
             @Argument perPage: Int,
             @Argument page: Int,
-            @Argument stateIn: List<ProcessInstanceState>
+            @Argument stateIn: List<ProcessInstanceState>,
+            @Argument variablesFilter: VariableFilterGroup?
     ): ProcessInstanceConnection {
         return ProcessInstanceConnection(
-                getItems = { processInstanceRepository.findByStateIn(stateIn, PageRequest.of(page, perPage)).toList() },
-                getCount = { processInstanceRepository.countByStateIn(stateIn) }
+                getItems = { processInstanceService.getProcessInstances(perPage, page, stateIn, variablesFilter) },
+                getCount = { processInstanceService.countProcessInstances(stateIn, variablesFilter) }
         )
     }
 
diff --git a/graphql-api/src/main/kotlin/io/zeebe/zeeqs/graphql/resolvers/type/BpmnElementResolver.kt b/graphql-api/src/main/kotlin/io/zeebe/zeeqs/graphql/resolvers/type/BpmnElementResolver.kt
index b867d74b..ae445c1b 100644
--- a/graphql-api/src/main/kotlin/io/zeebe/zeeqs/graphql/resolvers/type/BpmnElementResolver.kt
+++ b/graphql-api/src/main/kotlin/io/zeebe/zeeqs/graphql/resolvers/type/BpmnElementResolver.kt
@@ -5,9 +5,7 @@ import io.zeebe.zeeqs.data.entity.ElementInstanceState
 import io.zeebe.zeeqs.data.entity.Process
 import io.zeebe.zeeqs.data.repository.ElementInstanceRepository
 import io.zeebe.zeeqs.data.repository.ProcessRepository
-import io.zeebe.zeeqs.data.service.BpmnElementInfo
-import io.zeebe.zeeqs.data.service.BpmnElementMetadata
-import io.zeebe.zeeqs.data.service.ProcessService
+import io.zeebe.zeeqs.data.service.*
 import io.zeebe.zeeqs.graphql.resolvers.connection.ElementInstanceConnection
 import org.springframework.data.domain.PageRequest
 import org.springframework.data.repository.findByIdOrNull
@@ -41,6 +39,21 @@ class BpmnElementResolver(
                 ?: BpmnElementMetadata()
     }
 
+
+    @SchemaMapping(typeName = "BpmnElement", field = "extensionElements")
+    fun extensionElements(element: BpmnElement): BpmnExtensionElements? {
+        return findElementInfo(element)
+                ?.extensionElements
+    }
+
+
+    @SchemaMapping(typeName = "BpmnElement", field = "documentation")
+    fun documentation(element: BpmnElement): String? {
+        return findElementInfo(element)
+                ?.documentation
+
+    }
+
     @SchemaMapping(typeName = "BpmnElement", field = "process")
     fun process(element: BpmnElement): Process? {
         return processRepository.findByIdOrNull(element.processDefinitionKey)
diff --git a/graphql-api/src/main/kotlin/io/zeebe/zeeqs/graphql/resolvers/type/ProcessResolver.kt b/graphql-api/src/main/kotlin/io/zeebe/zeeqs/graphql/resolvers/type/ProcessResolver.kt
index 2a10a279..c57a7eba 100644
--- a/graphql-api/src/main/kotlin/io/zeebe/zeeqs/graphql/resolvers/type/ProcessResolver.kt
+++ b/graphql-api/src/main/kotlin/io/zeebe/zeeqs/graphql/resolvers/type/ProcessResolver.kt
@@ -6,6 +6,7 @@ import io.zeebe.zeeqs.data.repository.ProcessInstanceRepository
 import io.zeebe.zeeqs.data.repository.SignalSubscriptionRepository
 import io.zeebe.zeeqs.data.repository.TimerRepository
 import io.zeebe.zeeqs.data.service.BpmnElementInfo
+import io.zeebe.zeeqs.data.service.ProcessInstanceService
 import io.zeebe.zeeqs.data.service.ProcessService
 import io.zeebe.zeeqs.graphql.resolvers.connection.ProcessInstanceConnection
 import org.springframework.data.domain.PageRequest
@@ -19,6 +20,7 @@ class ProcessResolver(
     val timerRepository: TimerRepository,
     val messageSubscriptionRepository: MessageSubscriptionRepository,
     val processService: ProcessService,
+    val processInstanceService: ProcessInstanceService,
     private val signalSubscriptionRepository: SignalSubscriptionRepository
 ) {
 
@@ -27,20 +29,24 @@ class ProcessResolver(
         process: Process,
         @Argument perPage: Int,
         @Argument page: Int,
-        @Argument stateIn: List<ProcessInstanceState>
+        @Argument stateIn: List<ProcessInstanceState>,
+        @Argument variablesFilter: VariableFilterGroup?
     ): ProcessInstanceConnection {
         return ProcessInstanceConnection(
             getItems = {
-                processInstanceRepository.findByProcessDefinitionKeyAndStateIn(
-                    process.key,
-                    stateIn,
-                    PageRequest.of(page, perPage)
+                processInstanceService.getProcessInstances(
+                        perPage,
+                        page,
+                        stateIn,
+                        process.key,
+                        variablesFilter
                 ).toList()
             },
             getCount = {
-                processInstanceRepository.countByProcessDefinitionKeyAndStateIn(
-                    process.key,
-                    stateIn
+                processInstanceService.countProcessInstances(
+                        stateIn,
+                        process.key,
+                        variablesFilter
                 )
             }
         )
diff --git a/graphql-api/src/main/resources/graphql/Element.graphqls b/graphql-api/src/main/resources/graphql/Element.graphqls
index 4e84b9e2..d6bb264f 100644
--- a/graphql-api/src/main/resources/graphql/Element.graphqls
+++ b/graphql-api/src/main/resources/graphql/Element.graphqls
@@ -10,6 +10,12 @@ type BpmnElement {
     # the metadata of the BPMN element
     metadata: BpmnElementMetadata!
 
+    # extension properties of the BPMN element
+    extensionElements:  BpmnExtensionElements
+
+    # documentation of the BPMN element
+    documentation: String
+
     # the process that contains the BPMN element
     process: Process
     # the instances of the BPMN element
@@ -46,6 +52,7 @@ enum BpmnElementType {
     SCRIPT_TASK
     SEND_TASK
     INCLUSIVE_GATEWAY
+    GROUP
 }
 
 # Additional metadata that are defined statically on the BPMN element.
@@ -84,4 +91,24 @@ type UserTaskAssignmentDefinition {
     assignee: String
     # the candidate groups
     candidateGroups: String
-}
\ No newline at end of file
+}
+
+type BpmnExtensionProperty {
+  name: String
+  value: String
+}
+
+type IoMapping {
+  source: String
+  target: String
+}
+
+type ExtensionIoMapping {
+  inputs: [IoMapping]
+  outputs: [IoMapping]
+}
+
+type BpmnExtensionElements {
+  properties: [BpmnExtensionProperty]
+  ioMapping: ExtensionIoMapping
+}
diff --git a/graphql-api/src/main/resources/graphql/Process.graphqls b/graphql-api/src/main/resources/graphql/Process.graphqls
index 24dd7c93..0a9071eb 100644
--- a/graphql-api/src/main/resources/graphql/Process.graphqls
+++ b/graphql-api/src/main/resources/graphql/Process.graphqls
@@ -13,7 +13,8 @@ type Process {
     processInstances(
         perPage: Int = 10,
         page: Int = 0,
-        stateIn: [ProcessInstanceState!] = [ACTIVATED, COMPLETED, TERMINATED]): ProcessInstanceConnection!
+        stateIn: [ProcessInstanceState!] = [ACTIVATED, COMPLETED, TERMINATED]
+        variablesFilter: VariableFilterGroup = null): ProcessInstanceConnection!
     # the scheduled timers of the timer start events of the process
     timers: [Timer!]
     # the opened message subscriptions of the message start events of the process
diff --git a/graphql-api/src/main/resources/graphql/ProcessInstance.graphqls b/graphql-api/src/main/resources/graphql/ProcessInstance.graphqls
index acafefd8..de27d421 100644
--- a/graphql-api/src/main/resources/graphql/ProcessInstance.graphqls
+++ b/graphql-api/src/main/resources/graphql/ProcessInstance.graphqls
@@ -73,7 +73,8 @@ type Query {
     processInstances(
         perPage: Int = 10,
         page: Int = 0,
-        stateIn: [ProcessInstanceState!] = [ACTIVATED, COMPLETED, TERMINATED]
+        stateIn: [ProcessInstanceState!] = [ACTIVATED, COMPLETED, TERMINATED],
+        variablesFilter: VariableFilterGroup = null
     ): ProcessInstanceConnection!
 
 }
diff --git a/graphql-api/src/main/resources/graphql/Variable.graphqls b/graphql-api/src/main/resources/graphql/Variable.graphqls
index 29e38f97..b2ff88a1 100644
--- a/graphql-api/src/main/resources/graphql/Variable.graphqls
+++ b/graphql-api/src/main/resources/graphql/Variable.graphqls
@@ -14,3 +14,24 @@ type VariableUpdate {
     value: String!
     timestamp(zoneId: String = "Z"): String!
 }
+
+input VariableFilter {
+    name: String!,
+    value: String!,
+    comparisonOperation: ComparisonOperation!
+}
+
+input VariableFilterGroup {
+    variables: [VariableFilter!]
+    filterOperation: FilterOperation = OR
+}
+
+enum ComparisonOperation {
+    EQUALS,
+    CONTAINS
+}
+
+enum FilterOperation {
+    AND,
+    OR
+}
\ No newline at end of file