Google just added a new search feature to Google+ that allows you to filter search results by location. And here's how you do it:
First, perform a search within Google+. It could be anything - from sunsets, to football, to food and more. Once you reach the results page, click the "from everywhere" tab at the top of the results. There, just enter a city or a zip code to filter.
The location filter does a good job of targeting the specific areas that you want to browse. It pulls in surrounding areas as well - for instance, a search for "Food" in "Los Angeles" fetches results from the cities of Pasadena and Long Beach (both in Los Angeles County).
Here's what it looks like in action, as you'll see a search for football narrowed down to "Green Bay" shows a top post of a pic from Lambeau Field.
Of course, for a post to appear in the location-specific search results, the user will have had to tag the post with a location. This, at least initially, is leading to the location filters bringing up a lot of Google place check-ins.