Wilcity is using PlaceSearch API https://developers.google.com/places/web-service/search

As Google said: region — The region code, specified as a ccTLD (country code top-level domain) two-character value. Most ccTLD codes are identical to ISO 3166-1 codes, with some exceptions. This parameter will only influence, not fully restrict, search results. If more relevant results exist outside of the specified region, they may be included. When this parameter is used, the country name is omitted from the resulting formatted_address for results in the specified region.

EG: If you enter in vn (Vietnam) code as your restriction and if your customer enters in a character like h, All destinations in Vietnam that contain h character will get higher priority in the result.

But, if you enter in New York, the New York City in USA will be returned