A new feature in BI4.1 with SAP ERP universes is join detection. In my example below I am creating a universe against an ABAP function module, using join detection. First you must detect keys in the data foundation and then the join detection works.
In this video I also try using a list of values in a prompt against an SAP ERP universe.
A good reference is Integrating SAP BusinessObjects BI Platform 4.x with SAP NetWeaver which helped me search for the function module inside the Information Design Tool.