Assuming you are using StairMaker (the built-in tool) you may be able to get what you want with cut fill settings in the stair editor (I don't recall for sure though). Third party tools might do it but I am not sure about this.
One way I can think of (aside from custom GDL) would be to use complex profiles. This would require creating a profile for each different flight of steps and may mean drawing the plan views in 2D lines and fills. Another way would be to add fills in the section. Both of these add considerably to both the initial modeling and maintenance though.
Rubia Torres
