I want to stack several buildings on top of each other to create multi-level street. But building create this weird hole in the terrain. It oftem visible even with building places on the second level. Can i prevent this?

Also, is there any way to edit buidling spawn points in CS2? For example, i want to make elevated road and i want my building to be attached to this evelated road, so people and cars will spawn on the elevated level, not on the ground.