Поиск города по ширине и долготе (из navigator.geolocation) через гугл-карты. <script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>

geolocation

geocoder = new google.maps.Geocoder();


    function codeLatLng(latlng) {
    geocoder.geocode({'latLng': latlng}, function(results, status) {
      if (status == google.maps.GeocoderStatus.OK) {
        if (results[1]) {
            var city = results[1]["address_components"][2]["short_name"];
            var setPhone;

            switch (city) {
                case "Донецк":
                    setPhone = "Donetsk";
                    break;
                case "Макеевка":
                    setPhone = "Makeevka";
                    break;
                case "Мариуполь":
                    setPhone = "Mariupol";
                    break;
                case "Краматорск":
                    setPhone = "Kramatorsk";
                    break;
                default:
                    setPhone = "Donetsk";
                    break;
            }

            $('.b-phones__item[data-filial="'+setPhone+'"]').show().siblings().hide();

            // console.log(setPhone);
            // console.log(results[1]);
            // console.info(city);
        }
      } 
    });
  }

(function getLocation() {
    if (navigator.geolocation) {
        navigator.geolocation.getCurrentPosition(showPosition);
    }
  })();

function showPosition(position) {
    var _latlng = new google.maps.LatLng(position.coords.latitude,position.coords.longitude);
    
    codeLatLng(_latlng);
  }