You want to see all developers that are NOT linked by a record in authorized to the current project.
Make a new occurrence of Developers, Developers|All
Link it with the cartesian join operator so that all Developers appear in this portal. Then set up a Filter expression on the portal to omit records that have a linking "Authorized" record:
IsEmpty ( FilterValues ( List ( Authorized::_fkDeveloperID ) ; Developers|All::__pkDeveloperID ) )
IF using FileMaker 12 or newer, A calculation field using ExecuteSQL could also list all unauthorized developers.
Perfect! The formula stumped me, but now i understand it and it works great. Thanks...