Coming into this late and am a beginner at Archicad but was looking for a solution to the same problem and worked out how to do it so for the benefit of others like me who can't believe Archicad couldn't do it - it seems it can (v24 - so probably has happened since this post 9 yrs ago).
My solution was to create a Graphic Override - in this instance I wanted to draw a foundation plan of an existing slab with outline of the walls dashed above - created a new Foundation Plan Graphic Override and a couple of new rules to this effect so the edge of the slab showed in a thicker pen type and all walls showed in a dashed narrower line and turned off all cut fills. Then also created a similarly named Model View over ride that has all the doors and windows, curtain walls and everything else I didnt want also turned off etc (Why there isnt an option to address walls and slabs here is a mystery to me (or even under the layer tabs where it would be possible to alter the graphics of each element based on the Layer Combination of the output drawing - clearly the Graphisoft developers logic flows differently to mine).
Haven't worked out how to show foundation walls or slab edges below yet. Probably a way but just like this solution - sufficiently illogical and convoluted.
Still looking?
