There's only two surfaces where you can place a Portal, use the first as a reference point and often use the maze strategy to mark where you've been and where you haven't been.

Then you need to press a button in floor one before you look around in floor two for the next surface, after that, it's just a matter of using the portal you placed on the first panel and go back over there to go through, then you'll be done with this. Good Luck.