object-flatten.js

function isObject(value) {
  return typeof value === 'object' && value !== null;
}

function flatten(data, result = {}, prefix = '') {
  return Object
    .keys(data)
    .reduce(function (result, key) {
      const path = prefix ? `${ prefix }.${ key }` : key;

      if (isObject(data[key])) {
      	return flatten(data[key], result, path);
      } 

     result[path] = data[key];
     return result;
   }, result);
}

// {x:1, y:1, z:{a:1,b:2}} flattens to {x:1, y:1, z.a:1, z.b: 2}  

var data = { 
  x: 1, 
  y: 1, 
  z: { 
    a: 1, 
    b: 2, 
    z: { 
      x: 100, 
      a: { 
      	a: 2 
      } 
    } 
  } 
};

console.log(
  flatten(data)
);