On my Facebook page, I posted a link to my YouTube video. When I was using the Facebook search to find a page, I was surprised to find that my link showed up and it said that 4 people shared it. Is there a way to find out who these people are, and where they shared my link?
You will be limited to seeing only the people who shared the link publicly (according to their privacy settings).
Finding how many shared your link on Facebook is a three step process:
you need to own that page to see haw many peoples had shared your link
you need to use facebook as you page (in my case www.facebook.com/zevrat)
in the search box type the part from the title of your link to see the results