Firstly, ensure that the Person you wish to restrict the permissions for has the role of Owner, Manager or Supervisor.
1. Go to Company Settings > User Restrictions
2. Here you will see all your companies Administrators listed (Owners, Managers and Supervisors)
3. Click "Edit" for the Person you wish to restrict the permissions for > Restrictions > Restricted Records > select the Departments, Locations and Local Entities you want that Person to have access to
4. Press "Save"