Если вы отключите все элементы карты, а затем добавите новый слой (одну страну), то будет видна только одна страна. Вот это jsfiddle https://jsfiddle.net/gvvy5vxz/2/
function initialize() {
var mapOptions = {
zoom: 5,
center: myLatlng,
mapTypeId: google.maps.MapTypeId.ROADMAP,
backgroundColor: '#FFF',
disableDefaultUI: true,
draggable: false,
scaleControl: false,
scrollwheel: false,
styles: [
{
"featureType": "water",
"elementType": "geometry",
"stylers": [
{ "visibility": "off" }
]
},{
"featureType": "landscape",
"stylers": [
{ "visibility": "off" }
]
},{
"featureType": "road",
"stylers": [
{ "visibility": "off" }
]
},{
"featureType": "administrative",
"stylers": [
{ "visibility": "off" }
]
},{
"featureType": "poi",
"stylers": [
{ "visibility": "off" }
]
},{
"featureType": "administrative",
"stylers": [
{ "visibility": "off" }
]
},{
"elementType": "labels",
"stylers": [
{ "visibility": "off" }
]
}
]
};