You can create groups and assign an user to be part of one or multiple groups. Ex- Supervisor can be assign to manage 2-3 groups.
To assign group to the user, you must have Administrative rights.
1- Go to Setting then Administration
2- Select the user you wish to edit. Located on the left side of the screen
3- Click Edit User Profile
4- Select the group from the drop down and click Add - The groups must be created first. See "How to create groups"
5- To delete a group assign to this user, click on the red X, next to the group name.