change states as well as navigating to another screen

Question

I have a navigation container that calls a function to my stack. I would like to navigate to a tab screen from a stack screen AND change a state in that tab screen. I have given some code below and a demo. In the demo you can see on screen3(stack screen) I am trying to navigate to Home(tab screen) and change a state so that it renders the MapHome screen.

I am unsure how to pass the state to the bottom tab screen without rendering it elsewhere. I appreciate any insight more than you know.

here is my demo as well as some code below of App.js. You must run the demo in IOS or android, it will not work for web.

import React from 'react';
import { StyleSheet, Text, View } from 'react-native';

import { NavigationContainer } from '@react-navigation/native';
import {createStackNavigator} from '@react-navigation/stack';
import { createBottomTabNavigator } from '@react-navigation/bottom-tabs';
import { MaterialCommunityIcons } from '@expo/vector-icons';

import Home from './Home'
import ListHome from './screens/screen1'
import MapHome from './screens/screen2'
import Screen3 from './screens/screen3'

const Tab = createBottomTabNavigator();

function MyTabs() {
  return (

    <Stack.Navigator
     initialRouteName="Home">        
      <Stack.Screen name="Home" component= {Home} options={{headerShown: false}}/>
      <Stack.Screen name="Screen1" component= {ListHome} options={{headerShown: false}}/> 
       <Stack.Screen name="Screen2" component= {MapHome} options={{headerShown: false}}/>
    </Stack.Navigator>
);
}


export default function App() {

  return (
   <NavigationContainer>
    <Tab.Navigator
    initialRouteName="Home"
    screenOptions={{
      tabBarActiveTintColor: '#F60081',
      tabBarInactiveTintColor: '#4d4d4d',
      tabBarStyle: {
        backgroundColor: '#d1cfcf',
        borderTopColor: 'transparent',
      },
    }} 
  >
    <Tab.Screen
      name="Home"
      component={MyTabs}
      options={{
        tabBarLabel: 'Home',
        headerShown: false,
        tabBarIcon: ({ color, size }) => (
          <MaterialCommunityIcons name="home" color={color} size={size} />
        ),
      }}
    />

     <Tab.Screen
      name="Screen3"
      component={Screen3}
      options={{
        tabBarLabel: 'Screen3',
        headerShown: false,
        tabBarIcon: ({ color, size }) => (
          <MaterialCommunityIcons name="account-group" color={color} size={size} />
        ),
      }}
    />
    
  </Tab.Navigator>
</NavigationContainer>
);
}

const Stack = createStackNavigator();

Answer 1

You can pass a parameter from Screen3 to the Home screen.

I have forked your demo and did some small refactoring (including changing from Class to Function components just for preference) so you may need to adapt it to your needs. You can find it here.

In Screen3 you can modify your onPress logic to the following:

navigation.navigate('Home', {
  screen: 'Home',
    params: {
      componentToShow: 'Screen2'
    }
});

Here's a breakdown of why you are seeing Home twice:

navigation.navigate('Home', {       // <-- Tab.Screen name. 
  screen: 'Home',                   // <-- Stack.Screen name.
    params: {
      componentToShow: 'Screen2'
    }
});

With this code you are now passing a route.param to the Home screen. I've included a useEffect to run any time route.params changes.

const [whichComponentToShow, setComponentToShow] = React.useState("Screen1");

React.useEffect(() => {
  if(route.params && route.params.componentToShow) {
    setComponentToShow(route.params.componentToShow);
  }
}, [route.params]);

Now, whenever a User navigates to the Home screen and a componentToShow route parameter is provided, the Home screen will update.