I am applying for Postgraduate degree research but for that I need to submit a Research Proposal with the application and it is very confusing for me because I never did any kind of research before.

I have been a small business owner for the last 7-8 years and I want to do research in the same field (Entrepreneurship or small- or family-business related), but I just don't know how to narrow down and select a specific topic.

Can you suggest some guidelines to select a topic?