This article explains how to set up and manage the synchronization between AD (Active Directory) & the OnePlan Resource Center.
Go to the Admin pages, select Users in the navigation, then expand the AD Synchronization topic heading.
Expand the AD Groups to Synch drop down see all AD groups. Multi-select the desired groups to synch.
The synchronization is an Add-Only synch, meaning, if you remove groups from the selection, users will not be deleted from the Resource Center.