He means you need to have some sort of variable or way to keep track of what the last room/door was. So right before you change layouts, set a variable to either a value of your choosing or the layout name if you don't have multiple doors between two rooms.
Then, on the start of your layout, check what that location variable is set to and reposition the player based on that. This is an excellent place to use sub events for good organization.
So On Start-
If location = a, set position to whatever
If location = b, set position to a different place
And so on.