Code HTML :

<div id="id01">
  {{firstName}} {{lastName}}
  <div id="id02">
    {{childFirstName}} {{childLastName}}
  </div>
</div>

Code JS :

var myObject = {"firstName" : "John", "lastName" : "Doe"};
w3.displayObject("id01", myObject);

var myObject2 = {"childFirstName" : "Thibaut", "childLastName" : "PIGNÉ"};
w3.displayObject("id02", myObject2);