Navigation:  System Setup (F4) > Users > Site Access Tab

OVERRIDE LIST OF SITES THIS USER CAN ACCESS:  A User can be set up to only see certain sites.  If there are no values configured, the User Group list of sites will be used.

 

THE USER WILL:  Only be allowed to access sites with this Account Manager, only be allowed to access sites with this Site Group code, or be managing users with this Manager code.