(This is getting rather far from the topic...)
This is a dynamic thing that would work similarily to RTB's setting system, except in a tree where every node with sub-nodes is expandable and initially closed. It is not a mere GUI. It is intended to handle a very large number of settings for fine-tuning where the average user only cares about the higher level controls, making it just about the ideal structure, and unfortunately, as far as I could find, the engine doesn't have anything like it. Think of those installers where if you select custom install, you get a tree of checkboxes where each is checked, unchecked, may have children, each child can be checked, unchecked, have children of it's own, etc. and the average user won't bother with most of the deepest settings, but they are there for the advanced users.
NOT a GUI. (Although I am just getting to the part where I need to create the GUI code.)