to put it visually:
Scene Behavior: spawn player scene one>>>>Move to end of level and Exit Scene One>>>>>>Then Load player at x+y Scene Two. Check?
<<<<Exit Scene Two from left side<<<<<<(return to scene one)
Load scene One but Override original Spawn actor at x+y and load character at new x+y.
You can make regions at the ends and beginning of the scene (or doors, or whatever) which trigger the scene behavior. If you exit level two from the right you go to scene 3, if you exit it from the left, you go BACK to scene one, but the region at the left overrides the previous level's spawn behavior. That way you don't have two players at the same time. Also, make sure you don't just place the player in the game (except for testing maybe), because the player needs to spawn via code, or you will always have two players running around when the scene loads.