Reusing tilemap segments

Hi,

I'm wondering what is the "best practice" workflow for reusable tilemap segments. For example out of my tile palette I construct a room and I want to reuse it in multiple places.

Is there some way to "prefab" a section of a tilemap? I haven't found such a thing.

Or perhaps I should just prefab the whole tilemap, and use multiple tilemap objects within one grid? Won't that introduce significant overhead?

Thanks for any help!