Yes, prefabs can certainly spawn prefabs via script, but you need to think about a few things, instead of using level load inside a prefab, use a timer and set the trigger time to 1, not -1. The reason for this is that it can crash if you do level load inside a prefab that you spawn later than on the actual level load.
Tilemaps can't be included, since they are locked inside the level, you will need to create the floor as a separate doodad OR paint the floor in general where you will spawn the prefab, like I'm doing in the cave for my random parts.