From time to time, Service Catalog administrators may want to review some offering group permission and want to know if such a report exists so they can run the report to show the offering group permissions.
Service Catalog 17.3 and higher
There is no such a report that Service Catalog Administrators can run.
Admins could use the export tool to export certain offering with "Include permissions" checked
and if the offering is using group permission you will see them in the exported xml file.
This techdocs link descript how to export/import an offering