1. Once you have a workgroup created, you can add employees to that group to collaborate. Click on Workgroups to the left side of your screen and then click on the workgroup to add a user. 

2.  From there, scroll down to Workgroup Members and click on EDIT to add a new member 

3. Then click on the box to add additional users and hit SAVE

Note: Users may only belong to one workgroup at a time. 

Note: Whenever there are changes made to the workgroup (adding/removing users or deleting/re-creating workgroups), it is important to have all the users within that workgroup sign out and login again to reflect the changes on their end.