You can remove user group definition(s) which are created by you, which do not
have any mapped users, and which are no longer required, by deleting from the User
Group Maintenance window.
Select the checkbox adjacent to the user group ID(s) whose details are to be
removed.
Click Deletein the User Group tool bar.
Click OK in the information dialog to confirm deletion.
Note:
User Groups cannot be deleted if any requests (Domain map/unmap and Role
map/unmap) are pending for authorization or any users are mapped to
it.