title: Defining a NavHostFragment inside another fragment
body: <p>I have a fragment that I define a NavHostFragment inside it like this: </p>
  
  <pre><code>&lt;fragment
          android:id="@+id/shipping_host_nav"
          android:name="androidx.navigation.fragment.NavHostFragment"
          android:layout_width="0dp"
          android:layout_height="wrap_content"
          app:layout_constraintLeft_toLeftOf="parent"
          app:layout_constraintRight_toRightOf="parent"
          app:layout_constraintTop_toTopOf="parent"
          app:navGraph="@navigation/shipping_nav_graph"
          app:defaultNavHost="true"/&gt;
  </code></pre>
  
  <p>when trying to call findNavController method in the fragment it threw an illegal state exception and says that my view group doesn't have a NavController. </p>
  
  <pre><code>    java.lang.IllegalStateException: View androidx.core.widget.NestedScrollView{1dd5506 VFED..... ......I. 0,0-0,0} does not have a NavController set
  </code></pre>
  
  <p>So my question is: <strong>can I define a NavHostFragment inside another fragment?
  or suitable for activity only?</strong> 
  I have searched a lot to find can I define a nav host fragment inside another fragment but I didn't find any answers. </p>