How to make a multiple world/Dimension replicated ? (like a Nether world)

How could i make a fully replicated alternative dimension ? Like Minecraft, for example.

How can i do a Nether dimension in UE ? It is at least possible ?
Not a new large world necessarily, but a little lobby ? but the others people will continue to play on the real world

It is something to do with Streaming Level ?

Thanks a lot for your help !