title: React-native: Go back to a specific screen in stack
body: <p>This is the root navigator</p>
  
  <pre><code>export const AppNavigator = StackNavigator({
          Splash: { screen: Splash },
          Dashboard: { screen: DashboardDrawer }
      });
  
  const DashboardDrawer = DrawerNavigator({ DashboardScreen: {
          screen: StackNavigator({
              A: { screen: A },
              B: { screen: B },
              C: { screen: C },
              D: { screen: D },
          }
      }, {
          contentComponent: DashboardDrawerComponent,
          drawerWidth: 280
      });
  </code></pre>
  
  <p>I have 4 screens - A, B, C, D in my stack.
  I want to jump from D to A. (or D to any screen)
  I referred to the following react-navigation documentation-<a href="https://reactnavigation.org/docs/navigators/navigation-prop#goBack-Close-the-active-screen-and-move-back" rel="noreferrer">https://reactnavigation.org/docs/navigators/navigation-prop#goBack-Close-the-active-screen-and-move-back</a></p>
  
  <p><em>The above doc. states that to go from screen D to screen A (popping D, C, and B) you need to supply a key to goBack FROM, in my case B, like this</em></p>
  
  <pre><code>navigation.goBack(SCREEN_KEY_B)
  </code></pre>
  
  <p>So, my question is <strong>from where should I get the key for a specific screen?</strong> 
  I checked my root navigation object, and it shows me some dynamically generated key for each screen. <strong>How can I specify my own keys for the screens?</strong></p>