Filter values in the list based on the current location of the user

Hello everybody!
Does anybody know how to do filter in values based on current user location.
For example:
I have 1000 of customers all around the city. I come to location "1" and star to fill the form.
it is necessary that in the list of customers there will be only those values that fall into the buffer 100 meters around my current location, determined by the gps sensor of my mobile device.
THank you for help!

Hi, As far I know, this feature is not yet available on ODK. However, since ODK source code is open to all, you may customize and include that feature for your app.