Best Practice for Country, Region, City

Alright – I’m in the US, and setting up a nationwide directory. We have Country, Region, and City as options for hierarchy within locations for listings, and also what we can display on a map.

So I have the United States, then I have Tennessee as a Region, and then Nashville as a City. Problem is, I want to display a map that is centered on Nashville, but also shows listings in Brentwood, Franklin, and Murfreesboro, which are different cities, but all nearby. That being said, I don’t want to show the entire state.

Would it be better to start using Region not as a state, but as the Region I’m wanting to encompass, ie Nashville Metropolitan Area? I’m guessing State wasn’t used as a term, since not all countries are set up like the US, but I’m just not sure what the best way is to do this.

Thanks!