Limit Preview to specific folders?

I’ve been searching around for what options there are with file previews and I haven’t been able to find an answer to this question: is it possible to limit preview generation to specific folders? For example say I have a Shared folder that has documents, images and movies in it that I want to generate previews for, but I don’t want previews generated for anything outside of that Shared folder. Is that possible?

Have you tried to create a .nomedia file on the mentioned folder?