Find within Radius.

db.places
      .find({
        location: {
          $geoWithin: {
            $centerSphere: [[-122.462621, 37.770100], (1 / 6378.1)]
          }
        }
      })
      .pretty()

It takes two arguments, first cordinates and second radians for distance value. For 1 Km radian value is 1 / 6378.1 for 2 Km it is 2 / 6378.1. For 1 mile it is 1 / 3963.2