title: Android NavController move to another host destination
body: <p>I have a question regarding to <code>NavController</code>:</p>
  
  <p>There is the scheme (sorry for my painting, hope it helps :D)</p>
  
  <p><a href="https://i.stack.imgur.com/dvDsy.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/dvDsy.png" alt="enter image description here"></a></p>
  
  <p>I have <code>MainActivity</code> and <code>BottomNavigationView</code> with 3 tabs: <strong>A, B, C</strong>.</p>
  
  <p>When I tap to <code>A</code> it opens <code>Fragment A1</code> and there is <code>next button</code> which opens <code>Fragment A2</code>.</p>
  
  <p>In <code>Fragment A2</code> there are buttons <code>back</code>, <code>next</code>, no problems with navigation here.</p>
  
  <p>The problem is when I need to navigate from <code>Fragment A2</code> to <code>section B</code> the same like a click on <code>B</code> in <code>BottomNavigationView</code>.</p>
  
  <p>The problem is that it's different graph, how to switch them?</p>
  
  <p><strong>My ideas:</strong></p>
  
  <ol>
  <li><p>I found work-around: <code>requireActivity().bottomBar.selectedItemId = R.id.graph_b</code> but it's not good idea.</p></li>
  <li><p>I would like to achieve it using <code>navigation component</code>. I was trying to do <code>findNavController().navigate(R.id.graph_b)</code>, but it leads to crash:</p></li>
  </ol>
  
  <blockquote>
    <p>java.lang.IllegalArgumentException: navigation destination
    com.my.app.staging:id/graph_b is unknown to this NavController</p>
  </blockquote>
  
  <p>How to make it using <code>NavController</code> ? </p>
  
  <p>There is Google Example project with all architecture:
  <a href="https://github.com/googlesamples/android-architecture-components/tree/master/NavigationAdvancedSample" rel="nofollow noreferrer">https://github.com/googlesamples/android-architecture-components/tree/master/NavigationAdvancedSample</a></p>
  
  <p>And to simplify my question I've added a button in this project, where on click should opens different screen:</p>
  
  <p><a href="https://i.stack.imgur.com/fD7d6.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fD7d6.png" alt="enter image description here"></a></p>