Hello
I tried it out for you today: a 4 cm federal file fits in the front compartment, two only with luck, depending on the filling level. A 7 cm federal file only fits if it is only half full.

At first I would have said that a 7cm folder would fit in there without any problem. But towards the bottom, the compartment tapers a lot, so it's really tight, as Philippgoo has already said.