title: How to show child elements as parents using angular 6 ngFor
body: <p>I have a JSON data set which itself is an array, and each object may contain sub arrays.</p>
  
  <p>I need to show the elements in the inner nested array as elements of parent array, to be displayed using Angular <code>NgFor.</code></p>
  
  <p>The following is my input format:</p>
  
  <pre><code>[{
    'id': 1,
    'title': 'One',
    'data': [{
      'id': 200,
      'dataset': [{
          'id': 300,
          'name': 'Duke',
        },
        {
          'id': 301,
          'name': 'Bajaj'
        }
      ]
    }]
  }]
  </code></pre>
  
  <p>I need to display as:</p>
  
  <pre><code>1  One (outer element)
     300   Duke (innermost element)
     301   Bajaj
  </code></pre>