Steps to reproduce:

1. Limit access to problems by using tags for a user group (Administration > User group > Tag filter)
2. Save changes
3. Try to roll back the change (i.e. remove all the tag filters)

Result:
You should click "Remove" N times (one time per each host group). What if you have 100 (or 1000) groups in the list

Expected:
It would be great to be able to select all (or some of them) in this situation.