We create a dynamic group to get the current users in a specific OU, region, office, department or any other filter, is helpful because you always have active users, which means that all disable users are not part of this group (or distribution list). but sometimes you need to be sure if a user belongs to this group, and therefore you need to execute the follow lines in Exchange PowerShell:
first, to retrieve all members of the dynamic group:
once you have all the information in the $Dyn variable, the next step is filter the information:
and you can see the information in PowerShell, but if you have a huge amount of users there, then you can export the information to a csv file:
And then use excel to search, filter or just store the file as record.
I hope this can be useful for you.