nav.js

import React from "react";
import { StyleSheet, Text, View, TouchableOpacity } from "react-native";
import { StackNavigator } from "react-navigation";

const Home = ({ navigation }) => {
  return (
    <View style={styles.container}>
      <TouchableOpacity onPress={() => navigation.push("OtherStack")}>
          // push will only go to "OtherStack" but because we are now inside of "OtherStack" and it's new nested StackNavigator. There is no "OtherStack" just "Meow" and "Blue".
          // If we do "navigate" instead it would keep navigating forever
        <Text>Go To Profile</Text>
      </TouchableOpacity>
    </View>
  );
};

const Profile = ({ navigation }) => {
  return (
    <View style={styles.container}>
      <TouchableOpacity onPress={() => navigation.goBack()}>
        <Text>Go Back</Text>
      </TouchableOpacity>
    </View>
  );
};

const Other = StackNavigator({
  Blue: {
    screen: Home,
  },
  Meow: {
    screen: Profile,
  },
});

const RootNavigator = StackNavigator({
  Home: {
    screen: Home,
  },
  Profile: {
    screen: Profile,
  },
  OtherStack: { 
    screen: Other 
  },
});

export default class App extends React.Component {
  render() {
    return <RootNavigator />;
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: "#fff",
    alignItems: "center",
    justifyContent: "center",
  },
});