We can do this via the content api using itemtype 'Metric' For example:
(get-PersonalFolder ).children | where {$_.itemtype -match 'Metric'}
createdAt : 11/22/2020 11:23:18 PM
createdBy : 0000000000BC774E
modifiedAt : 11/22/2020 11:23:18 PM
modifiedBy : 0000000000BC774E
id : 00000000011EB967
name : Metrics Example
itemType : MetricsV2
parentId : 0000000000EDB78E
permissions : {GrantEdit, View, Edit, GrantView…}
createdAt : 11/22/2020 11:30:47 PM
createdBy : 0000000000BC774E
modifiedAt : 11/22/2020 11:30:47 PM
modifiedBy : 0000000000BC774E
id : 00000000011EE063
name : Short title
itemType : Metrics
parentId : 0000000000EDB78E
permissions : {GrantEdit, View, Edit, GrantView…}
Get-MetricsSearchById -id 00000000011EE063
logQuery : my_metric | timeslice 1m | count by _timeslice
title : Short title
description : Long and detailed description
metricsQueries : {@{rowId=A; query=my_metric | avg}}
desiredQuantizationInSecs : 60
properties : { \"key\": \"value\" }
createdAt : 11/22/2020 11:30:47 PM
createdBy : 0000000000BC774E
modifiedAt : 11/22/2020 11:30:47 PM
modifiedBy : 0000000000BC774E
id : 00000000011EE063
parentId : 0000000000EDB78E
create from example file and save to the personal folder.
$mq = Get-Content -Path ./library/metricsearch.json | ConvertFrom-Json -Depth 10
$mq.parentId = (get-PersonalFolder ).id
New-MetricsSearch -body $mq