I only recently became aware of this myself, but I've used it to get the same citations that my competitors have inside a single city. First, you want to go to Google and type in keywords local to the city you're targeting. Say you want to rank on Google for "dentists denver colorado"- You would type in those keywords and look on the Google results page for high-ranking Google Maps results. Take the addresses you find from there, and put them into ScrapeBox with quotes surrounding the actual street name. This is so that you don't have to sift through results that only have the street name or road name in them, you want to get only the address you are finding backlinks of. Then, you set up the harvester and grab your results. Remove any results that are from the websites of those addresses, and you're left with a solid list of hyperlocal business directories or locations that you can possibly get business citations from. Edit: I've also found a few PBNs doing this, not sure if this is useful information to have or not.