如何使基于谷歌api的城市仅自动完成输入

I am new google places auto complete api. I want to self complete for only cities. When you enter a city such as London, London city can be visible but also another places can be visible.I dont want these that are related to not city name.In short, I want self complete works with only city names. Below is my code. I am unable to correct code. Please help meI am new google places auto complete api. I wan