Is there a function similar to RH_GET_ORG_ASSIGNMENT that returns the position instead of the organization unit? Also, what function group does the RH_GET_ORG_ASSIGNMENT belong to?
RH_GET_ORG_ASSIGNMENT belongs to function group RHGO. To see this go to transaction SE37 and display RH_GET_ORG_ASSIGNMENT. Click on the tab for ATTRIBUTES and it will show you the function group. To my knowledge a version that returns position does not exist. One could be built but once you have the Org unit you can derive the information.