// LoginRouter.js
const LoginRouter = createStackNavigator(
  {
    Login: Login,
    Register: Register,
    Dashboard: DashboardRouter
  },
  {
    initialRouteName: "Login"
  }
);

// DashboardRouter.js
const TabNavigator = createBottomTabNavigator(
  {
    MessageRouter: MessageRouter,
    AddressRouter: AddressRouter,
  },
  {
    ...
  }
);

// AddressRouter.js
const AddressRouter = createStackNavigator(
  {
    // these all navigator will become a nested navigation
    Address: Address,
    UserAdd: UserAdd,
    UserGroup: UserGroup
  },
  {
    initialRouteName: "Address"
  }
);