Community
I would try/consider two routes.
-Multiple building pads. You can create building pad with a slope. So one pad for the flat areas and several for the sloped area
During creation of the buidlig pad there is possibility to add a sloping arrow.
-Start with bigger (square) building pad and fill it up with material for the sloped parts.
Louis
Please mention Revit version, especially when uploading Revit files.