Brand New, need help on feasible location changing

Questions:

1. Is there any way to group all cities by a metro. I live in a metro full of several cities. What I’d like to do is have the user click Dallas/Ft Worth (DFW) metro for example and all businesses in the DFW Metropolitan area (no matter the city) pop up on a map that defaults to that location. If they were to click Houston Metro, all businesses in the Houston Metro will pop up (no matter the city ) and the map default location will center somewhere in Houston.

I know there’s a change location option but it’s not feasible. For one: There’s no need to select country because I only want US. I only plan on launching this directory in a few large metros across the US. As far as the metros, there’s so many cities in one metro and allowing the user to click only one city takes all the businesses in nearby cities off the map.