Ability to share a project

I've been using NotebookLM (as well as Perplexity Spaces) quite regularly. What I often do is upload a bunch of PDFs (high quality business pitchbooks) and then upload something I'm working on and ask for a detailed comparison.

I'd love to be able to share this type of functionality with co-workers, except I don't want them having access to the comparison set of documents (or even knowing what they are). I understand there is no API currently available.

Any suggestion how to achieve something like this? Another idea would be to fine-tune a model based on the comparison documents, but that seems even more difficult.