JSFiddle - React, Tailwind, and code Playground

JavaScript

var obj = {
  foo: { bar: 'baz' }
};

var deep_value = function(path){
    var obj = path.split('.');
    obj = obj[0];
    for (var i=0, path=path.split('.'), len=path.length; i<len; i++){
        obj = obj[path[i+1]];
    };
    return obj;
};

alert(deep_value('obj.foo.bar'));