Currently, a Group Admin is able to trace a given user's contacts across different groups / locations / countries that he is not even admin of.

This is contradictory to the concept of the Group Admin only being able to administer settings and users of groups he is admin of / permitted to administrate.

It also raises issues regarding data protection because now an administrator who is a group admin of e.g. only one single specific group in one specific country can trace contacts of any user for any country.

A more appropriate behaviour would be that if a Group Admin runs a Contact Report he should only be shown the results from the group(s) he is admin of. Same goes for Location or Country Admins.