In empower® you have the possibility to provide users with individual permissions to specific folders. For this purpose a search dialog is used to search for the users on the Active Directory, here you may need Trusts to access different domains in the Active Directory Forest.
Moreover, the starting point, from which the search is performed, can be set under "PermittedADGroups" in the database table tbl_SettingsPlain or via the Empower Server Wizard under "BrowsableADGroups". Here you are able to add one or more user groups (incl. the domain).