Generally the more specific your "requirement" is the more specific you have to get. So if you are looking for something specific you want to (to borrow a YC quote) "do things that doesn't scale". Talk to former faculty, colleagues and other contacts. Manually look up companies who do research or have business in your field. Make diagrams, charts and spreadsheets if you have to. That is how you would find the things that no one would generally advice you to do since they wouldn't know about them because it would be specific to your situation. (I hope that made sense).