Tree structure implementation in SELECT (plugin search)?

Question

nested set

Hello.
Faced the following problem:
There is a nested sets tree with thematic lesson plans (Direction, subject, section, topic, lesson, etc. organized into a tree)
There is a need to select from this tree, both a leaf and possibly a node.
It is desirable to organize this in a select (when submitting the form, I need the id of the selected element to the server).
Standard certainly will not work here? but perhaps there is a suitable plugin.
At one time I saw a similar one (it completely created a new structure from DIV) which, according to the description, could draw a tree, but foolishly did not download it. I thought when I need to find it, but now I can not find it.