title: react-navigation: is this really the only way to access sibling and parent navigators?
body: <p>So, I have a somewhat complicated nesting of navigators in my app (4 layers), and it is useful to be able to grab data from the params of each. </p>
  
  <p>For instance, I have tabs, within tabs, that are inside a stack navigator. To access params from one of the screens therein I have do this:</p>
  
  <p><code>const homeSiblingNavigator = props.navigation.dangerouslyGetParent().dangerouslyGetParent().getChildNavigation('Home');</code></p>
  
  <p>First of all, calling <code>dangerouslyGetParent()</code> inspires absolutely no confidence.</p>
  
  <p>Secondly, I feel like there should be a way, if you uniquely name every route, to find route by name.</p>
  
  <p>I'm thinking of writing some weird recursive/loopy route finder. But before I do, I'm curious if there is a better way.</p>