nesting drawer in tab nav

navigator.js

// in my MainTabNavigator

import RainMapScreen from '../screens/RainMapScreen';
import GroupMessageHistoryScreen from '../screens/GroupMessageHistoryScreen';
import GroupDrawer from './GroupDrawer'

export default createBottomTabNavigator(
  {
    GroupDrawer: {
      screen: GroupDrawer,
    },
    Messages: {
      screen: GroupMessageHistoryScreen,
    },
    Rain: {
      screen: RainMapScreen,
    },
  },

  {
    navigationOptions: ({ navigation }) => ({
      tabBarIcon: ({ focused }) => {
        const { routeName } = navigation.state;
        let iconName;
        switch (routeName) {
          case 'Summary':
            iconName = Platform.OS === 'ios'
              ? `ios-information-circle${focused ? '' : '-outline'}`
              : 'md-information-circle';
            break;
          case 'SelectGroup':
            iconName = Platform.OS === 'ios'
              ? `ios-link${focused ? '' : '-outline'}`
              : 'md-link';
            break;
          case 'Settings':
            iconName = Platform.OS === 'ios'
              ? `ios-options${focused ? '' : '-outline'}`
              : 'md-options';
        }
        return (
          <Ionicons
            name={iconName}
            size={28}
            style={{ marginBottom: -3 }}
            color={focused ? Colors.tabIconSelected : Colors.tabIconDefault}
          />
        );
      },
    }),
    tabBarPosition: 'bottom',
    animationEnabled: false,
    swipeEnabled: false,
  }
);

// -------------------- DIFFERENT FILE -------------------------------

// in my GroupDrawer
import { createDrawerNavigator } from 'react-navigation';

import SummaryScreen   from '../screens/SummaryScreen'
import SettingsScreen  from '../screens/SettingsScreen';
import GroupHelpScreen from '../screens/GroupHelpScreen'
import ContactScreen   from '../screens/ContactScreen'



const GroupDrawer = createDrawerNavigator ({
    Summary: {
      screen: SummaryScreen,
      navigationOptions: {title: 'Summary'},
    },
    Profile: {
      screen: SettingsScreen,
      navigationOptions: {title: 'profile'},
    },
    Contact: {
      screen: ContactScreen,
      navigationOptions: {title: 'contact'},
    },
    Help: {
      screen: GroupHelpScreen,
      navigationOptions: {title: 'help'},
    },
  

});

export default GroupDrawer;

// in navigator.js, add this:

export default class MainScreen extends Component{
  static router = MainTabNavigator.router;
  render() {
    return (
      <MainTabNavigator
        navigation={this.props.navigation}
      />
    );
  }
}

// that's your main screen

const GroupDrawer = createDrawerNavigator({
  Main: { screen: MainScreen },
}, {
    // contentComponent: props => <SideBar {...props} />,
  });

export default createAppContainer(GroupDrawer);

// I hope, this will help you.