Even though you already have the answer, here’s the explanation.
Relating this to episode, you look at the layers. I will be labelling the layers 1 to 5, 5 being the top layer.
The tyre tracks, which belong to the car, are on the bottom [1st] layer; therefore, the maid left first.
The bike tracks are above the car but below the motorcycle tracks, so the handyman left second.
The motorcycle tracks are above the car and bike tracks but below the footsteps and paw prints so the cook left third.
The green set of footsteps are above everything already listed, therefore, the butler was the fourth to leave.
The paw prints and red footsteps are on the 5th layer, meaning that it was above everyone else’s. The nephew was the last to leave.