Would it be possible when adding category to offer categoryTree if known neerest categories or somehow offer a hint?

In Wikipedia not just newbies but also advanced editors usually dont know about possible categories and thus the dont set it into proper category or create duplicate.

In Wikiversity we have Projects (i.e. unit, which consist of more pages), which uses for certain reason a lot of categories - here it would be useffull to be able to choose from them directly from VE.