I see that it has been requested many times in the past, so I thought I would add a new post about it to see where it is at.
We desperately need a way to organize 3D Designs (and circuits and code blocks). The "Projects" feature is merely a bad excuse for "you can organize your stuff" because it is a filtering system, not a folder, and doesn't help in organizing the "root folder" of designs.
What we need is a simple system that works the same way any folders system works: the common directory tree. A single-tier system won't be good enough at all, but it would be better than nothing if you can't handle building the whole thing. (I have no idea why not, though. I have done it in my own database programming several times with no issue). Even adding preferred sorting to the list of designs is easy too (name, created date, last modified date/time) instead of only having mod-time as the only sorting.
Also, since it relates, why not have a recycle bin system too? I mean, it is a simple extension of a directory tree system anyway. (You know...add one more field to your table(s) to mark an item as 'deleted' instead of actually removing the record.)
I apologize if this comes across in a rude tone, but I can tell I'm not the only user who is frustrated by the lack of this feature, which really should have been part of the original release.