Cooperative experience with each player in a different level

Let me describe what i’m trying to achieve:

I have a large city map that one or more players exist in, in a cooperative manner. Some of the buildings in this city can be entered via interacting with a door. I want this interaction to take the player to a new level, which can be crafted by another designer, with their own traps, enemies, and obstacles.

However, I don’t want all of the players in the current game to be forced into the same building; so I want one player to be able to go into Building A, another into Building B, etc.

I have toyed with level streaming, and I can see that it could be a solution (stream Building A, place it some place completely out of view from the city, put player in it), but that feels like a hack. The reason I say this feels like a hack is because I cannot figure out how I can reference that level’s assets and probe it for it’s own player start so that I can easily place the player in the precise location that the designer wanted them.

I have also toyed with the console command ServerTravel, and that seems to just yank everyone along with it, which is not what I’m looking for.

So my question is, is there something that I haven’t tried yet, that is a common place solution?