Searching by a Location radius in Mercury Legacy Search is a great way to find Candidates based on where their home address is.
Start typing the name of the town, city or country etc. and look to select the location you are looking for as it comes up in the drop-down.
Make sure you select one with the 
icon.
The location will then be added to your criteria. By default the Radius sets to 30 miles from the geographic centre of the location. In this example below it's searching 50 miles from the centre of London. Simply click to change the Radius or change to Kilometres. You can also use the Boost feature to raise the importance of the location in your search.
Your results will then show.
If you need to get granular with your location the best practice would be to use an exact street address and set your radius from that. Mercury Legacy Search is integrated with Bing Maps so every address is in the system and can be searched from.