Splunk Authentication App

In the installation notes for the Centrify Auth app for Splunk, it says:

NOTE: You may also map an Active Directory group to a splunk role using group overrides in Centrify Express. For more information consult the Centrify Express admin guide.

There is nothing in the Centrify Express admin guide that mentions "group overrides".  Do I map AD groups to local linux groups and then name my Splunk roles the same as the local linux group?