Get name of previous route to go back to - react-native

Question

I have nested stacks in my app. With two different headers.
I have a reset but this just send the user back to the home screen regardless. How can I get the previous route?
resetForm() {
const { dispatch } = this.props.navigation;
const resetAction = StackActions.reset({
index: 0,
actions: [NavigationActions.navigate({ routeName: "Drawer" })]
});
this.props.navigation.dispatch(resetAction);
}
App Navigator:
const config = {
contentOptions: {
activeTintColor: "#e91e63",
inactiveTintColor: "#ffffff",
itemStyle: {
flexDirection: "row-reverse"
}
},
drawerWidth: 300,
overlayColor: "#003366",
drawerPosition: "right",
drawerBackgroundColor: "#009999",
transparentCard: true,
cardStyle: {
backgroundColor: "transparent",
opacity: 1
},
transitionConfig: () => ({
containerStyle: {
backgroundColor: "transparent"
}
})
};
const withHeader = (
screen: Function,
routeName: string,
Header
): StackNavigator =>
createStackNavigator(
{
[routeName]: {
screen,
navigationOptions: ({ routeName, props }) => ({
header: props => <Header {...props} />
})
}
},
{
initialRoute: "Home",
transparentCard: true,
cardStyle: {
backgroundColor: "transparent",
opacity: 1
},
transitionConfig: () => ({
containerStyle: {
backgroundColor: "transparent"
}
})
}
);
const routes = {
VideoEpisodes: {
screen: withHeader(VideoEpisodesScreen, "Video Episodes", DrawerHeader)
},
TestYourself: {
screen: withHeader(TestYourselfScreen, "Test Yourself", DrawerHeader)
},
MyResults: {
screen: withHeader(MyResultsScreen, "My Results", DrawerHeader)
},
BookmarkedVideos: {
screen: withHeader(
BookmarkedVideosScreen,
"Bookmarked Videos",
DrawerHeader
)
},
About: {
screen: withHeader(AboutScreen, "About", DrawerHeader)
}
};
const NestedDrawer = createDrawerNavigator(routes, config);
const MainStack = createStackNavigator(
{
Home: {
screen: HomeScreen,
navigationOptions: ({ props }) => ({
header: props => <BasicHeader {...props} />
})
},
Drawer: {
screen: NestedDrawer,
navigationOptions: ({ props }) => ({
header: () => null
})
},
VideoPlayer: {
screen: VideoPlayerScreen,
navigationOptions: ({ props }) => ({
header: props => <BasicHeader {...props} />
})
}
},
{
initialRoute: "Home",
transparentCard: true,
cardStyle: {
backgroundColor: "transparent",
opacity: 1
},
transitionConfig: () => ({
containerStyle: {
backgroundColor: "transparent"
}
})
}
);