getActionForPathAndParams.js

const AppNavigator = StackNavigator({
  login: {
     screen: login
  },
  screen1: {
    screen: Screen1
  },
  screen2: {
    screen: Logout
  }
});

const ActionForScreen1 = AppNavigator.router.getActionForPathAndParams(
    "screen1"
);

console.log(JSON.stringify(ActionForScreen1))
// {"type":"Navigation/NAVIGATE","routeName":"screen1"}