Departmental Admins: ability to view department's user group membership, user info/settings
To address privacy concerns around allowing any creator to view membership of any group, we have restricted group membership visibility so that "only the group creator or an administrator can view the specific users that are members of a group." Consequently, only admins are able to troubleshoot issues regarding user group membership or user settings issues.
In a large University such as ours with distributed IT services, it makes sense for departmental admins to have this level of access for the user group associated with their department's top-level folder. We understand that videographers can view group membership, but this access extends site-wide and cannot be restricted to a user group.
Judging from the documentation for custom roles and changing roles and access permissions for a user, a custom role cannot be created to address this need at the moment.
Wireframing this with words (ha!), I could imagine that a dept admin going to User Groups and searching for one associated with their Department's folder structure. For these groups, the Overview would be available, and selecting it would include the Membership tab. From the Membership tab, "Info" option would be included for each user.