What is the command to remove a user from AD group using Remove-QADGroupMember from the same domain and aswell as different domain?

I think the -Service switch is what you are looking for:

Remove-QADGroupMember -Identity $MyGroup -Member $MemberName -Service "DomainA.local"

Remove-QADGroupMember -Identity $MyGroup -Member $MemberName -Service "DomainB.local"

If you have Active Roles and all of your domains are managed by it, you could also try this:

# This will enumerate all instances of the group from all domains managed by Active Roles

Get-QADGroup -proxy -Identity $MyGroup | foreach {

Remove-QADGroupMember -proxy -Identity $_.DN -Member $MemberName 

}

In the second case, the assumption is that $MyGroup contains the Name/CN or samaccountname of the group.

In the second case, the assumption is that $MyGroup contains the Name/CN or samaccountname of the group.