After you have created the necessary user groups, you can assign users to those groups as needed. A user can be assigned to multiple groups.
Note: Assigning users to groups requires the "Password Administration" security right.
To assign users to a group
In the Security Rights Setup dialog box, do one of the following:
On the Users tab, under Select User, select a user. Then, under Assigned Groups, click Add.
On the Groups tab, under User Groups, select a group. Then, under Assigned Users, click Add.
The Assign Groups to Users dialog box appears.
If the dialog box was opened from the Users tab, the Users list contains the selected user.
If the dialog box was opened from the Groups tab, the Groups list contains the selected group.
Set up the following options:
Groups - To select the groups that you want to add users to, click Add.
Users - To select the users that you want to add to the selected groups, click Add.
Clinics - To select the clinics that you want the selected user groups to have rights in, click Add.
Click
the Add to Queue button 
.
Repeat steps 2-3 as needed.
Click Process Queue.
Click Close.