So I have a family that I split up and I want to move one of the inactive sims to a new world but I want to keep playing my active family in the current world, is there a way to do this? thank you for any advice!

We can pull sims into the actively simulated world, but no we cannot push them out. The only way to do this is to play the currently inactive household, move them to their new world, and then transition active gameplay back to the original world.