I'm looking for an application that would work like
nemo, except that you have the possibility to add various tags to each document (whether it be a pdf or a tex file or anything else). Let me explain a little better.
I have a bunch of documents that are right now organized in folders according to their topic. I try to organize them as well as I can according to topic, but I sometimes the topics aren't mutually exclusive. For example, if I have a book on numerical physics it would be on "numerical" or "computer" folder, but it's also physics. It can't be in both at the same time (I don't want to use symlinks for compatibility issues) so tags would be a pretty efficient way of resolving that.
I have tried Mendeley but it's just too heavy, slow and polluted, and isn't really like a file browser, it's more of a file reader.
I have also downloaded Zotero, which seemed kind of promising, but it doesn't seem to understand and reproduce my current folder-separation system.
Anyway, to be clear, I don't want to abandon my current folder-separation system. I'd like something to complement it. If there is/was a way to make Zotero automatically recognize and reproduce my folders in it, great. But I don't think there is.
EDIT: related to this question, which provides some solutions, but they all have lots of limitations.