Tested and works out great, would love this addition to be official. I also tried breaking it by giving weird folder names, but it seems to work out well.

Three small nitpicks:
1) Visually it could be a nice touch if the map icon jumps in similarly like the jazz2 font. The staticness of the map icons frame 1 of entering home cooked levels feels uncharacteristic for JJ2.
2) It would be nice to see your current folder you are looking into at all times to not get disorientated, maybe next to the "../"?
3) I found myself keep pressing escape to intent to go back one level in the folder, especially when scrolling somewhere midway through, but it goes back to the episode select.