well, you could do a track that goes from "station 1" goes through its layout then ends up back in "station 2" then the track leads from "Station 2" through another layout then into the back of "station 1", so effectively you have one coaster but with two stations and two chainlifts or launches. This works best if you put the 2 stations right next to each other and synchronise them.
I hope that clears it up ..... wasn't explained all that well, but I tried