title: Nodejs, how to get value in nested json object, middle keys are unknown
body: <p>I have following nested configuration object, and I want to get the value
  of key1, which means I want to return "value1", key1 is static, but
  randomGeneratedNumber and randomGeneratedName are dynamic from database.</p>
  
  <pre><code>configuration:{
   randomGeneratedNumber:
     {
         randomGeneratedName:
            {
              key1: value1,
              key2: value2
            }
      }
  }
  </code></pre>