JSFiddle - React, Tailwind, and code Playground
JavaScript
var s = '{"0":{"0":"Item 1","1":"","2":"","3":"","4":"","5":"","childs":{}}, "1":{"0":"Item 2","1":"","2":"","3":"","4":"","5":"","childs": {"0":{"0":"Item 2 - Sub 1","1":"","2":"","3":"","4":"","5":""},"1":{"0":"Item 2 - Sub 2","1":"","2":"","3":"","4":"","5":""}}}}';
var o = $.parseJSON(s);
var item = o["1"].childs["0"]["0"];
console.log(item);