When performing an export to show all users, the time spent cleaning out duplicate users who are in multiple groups is a nightmare! Since staff are able to add/remove themselves as often as they want, the group(s) they are in is always changing. In theory, having a check box next to the group name to designate the "Home Unit" for each employee, would resolve the issue. It would also help when running reports in the Report Console (ED+Peds+X-ray selection would be eliminated if the employee's "home unit" was ED).
Platform 6 includes the concept of assigning a user to a "Home Department"