Making custom level editor

This is all for a 2D game. I have a scriptable object levelList that contains level maps as scriptable objects. I'm trying to make an editor window where I just drag and drop prefabs on a 2D coordinate plane, and that saves to a certain level map. Is that possible? Is it also possible to have multiple objects at the same x and y so it could be an object sitting on the floor? Or is this functionality already existent and I just don't know about it?