@Slater, Jerry*
Thank you for the question and for using Microsoft Q&A platform.
In Microsoft Purview Premium (G5), custodian searches can be performed by entering individuals manually. However, there is no direct feature allowing users to search for custodians by group or office level. You would need to manually enter the custodians one by one when performing searches or holds on their data, such as mailboxes.
Additionally, you can use the Choose users, groups, or teams option to specify the mailboxes to search. You can use the search box to find user mailboxes and distribution groups. You can also search the mailbox associated with a Microsoft Team (for channel messages), Microsoft 365 Group, and Viva Engage Group.
https://learn.microsoft.com/en-us/purview/ediscovery-content-search
However, it is important to note that Microsoft Purview eDiscovery allows you to manage custodians and non-custodial data sources in a case. You can add individuals in your organization as custodians and identify and preserve custodial data sources such as Exchange mailboxes, OneDrive accounts, and SharePoint and Teams sites. You can also identify and preserve non-custodial data sources.
https://learn.microsoft.com/en-us/purview/ediscovery-managing-custodians
https://learn.microsoft.com/en-us/purview/ediscovery-manage-new-custodians
Hope this helps. Do let us know if you have any further queries.
If this answers your query, do click Accept Answer
and Yes
for was this answer helpful. And, if you have any further query do let us know.