Is it possible to set forum up to resemble Backpage?

[nicoleryan]

This is hard to explain, but I hope it makes sense.
I like how when you go to backpage, you are able to post an ad in a specific city, and your post to that city also shows up in the state.

Example 1: You post in Denver, Colorado. Anyone that goes to the Denver backpage is able to view your post. In addition, anyone that goes to the Colorado backpage is able to see your post.

I like how it gives the option to either view posts by city, or by state; and when you view by state, it bunches together all the posts (from every city in that state) in one place. Is there a way to do this?

Example 2: Say I post in Denver, CO -and- Boulder, CO -and- Colorado Springs, CO...
Is there a way to simply go to the Colorado forum, and have it combine for you all of the posts from these three cities, but still keep them separate to allow anyone to click the city to narrow it down and view a specific area?