Hey @sosab123, welcome to the forums, your project sounds really neat .
The question of how to instance spatialOS worlds comes up a lot in discussion. The majority of the discussion happens in this thread.
Here are the two main methods of instancing currently used by our community developers.
1. Stacking relatively flat worlds on the Y axis (the Titanfall 2 approach).
if you would want to make a hard separation (portals to other planes or whatnot) than you can do a bit of trickery. If your world is, like a lot of MMORPGs, restricted in its use of the Y axis then you can layer multiple locations on top of eachother. Do keep in mind that workers only partition on the X/Z plane and not on the Y plane; so if you stack too much activity on top of eachother then your workers may become distressed.
2. Segregating players by Entity Interest.
There are cool tricks you can do using Entity checkouts which mean you could actually have 2 groups running through the same dungeon with their own monsters. However if you have enough Players then there’s a logical point where you’ll still want to split the load so it makes sense just to take the remote dungeon approach from the get-go.
For the moment, I recommend trying one or a combination of the above. We are working on a more robust instancing solution and hope to share that with you soon.