I only want to manually apply labels only to some files/folders. I have some parts of the same project spread out through 3 folders: not in Dropbox, in Dropbox

I only want to manually apply labels only to some files/folders. I have some parts of the same project spread out through 3 folders: not in Dropbox, in Dropbox, in Public subfolder of Dropbox. It'd be really nice to have a unified view on those things. As in apply 'Dropbox' or 'Dropbox/Public' labels to some files. I know Dropbox has shared links, but I don't want to have to create and manage those all the time. It's just an example. Finally, I think a great way to organize files is by time created/modified. If you exclude the system or program generated files. Quite often I just want to find a file that I know I saved a few days ago (but no idea in which folder).