title: Angular 4 access child of child component
body: <p>I'm using ngx-charts line chart component which has a timeline inside.
  So the structure go like this : MyComponent -> LineChartComponent -> TimelineComponent.</p>
  
  <p>(where LineChartComponent is the component from the library)</p>
  
  <p>Having a reference to LineChartComponent is it possible to execute something like @ViewChild() on this reference to access the TimelineComponent ?</p>