It is custom script job.
You could manually remap positions to function :D, but seriously, it sounds like mapping positions to functions would be duplicate work. Because the relationship between the function is already inferred by the relationship with the org unit. Also, if you were to map positions to functions this would double the amount of work required to maintain the process (e.g. remove relationship for position-function AND org unit-function)
Rather than creating a new set of relationships (between functions and positions), it might be more efficient to use a report or even a query (nested) to answer the analysis questions relating to functions and positions. It depends on the kind of questions you'll need to answer.
I dont think a matrix model could be used effectively for this situation. There was a type of spider model I remember from Toolset 7.0 where you could show every relationship type, this could give you a visual representation of the link between functions and positions via the org units.
Also, I am aware of some 3rd party software called CogniViz that could create this view as well.
Well -- Found out that "SAP organizational elements mapping" model type facilitates mapping of Positions & Organisation Units with the "Corresponds to" relationship.
I think this would serve our purpose too (which is ofcourse not for SAP integration) -- Do you see any potential issues with this approach compared to using Matrix or any other models?
From the model type name, it seems to be for integrating ARIS with SAP SolMgr -- Could someone share more details on the same?