Nested routes / Tab reducer

Awesome work, this example really helped me forward!
Now i'm stuck at nested routes with Redux and the new NavigationExperimental. In this example there are three routes: 'first', 'second' and 'third'. What would the example look like if there were 2 modules/tabs with nested routes (first, second, third)?

For example:
- Home
- Home First
- Home Second
- Home Third
- Settings
- Settings First
- Settings Second
- Settings Third

I read about the tabreducer and I think this is applicable here, but I can't really figure out how to use it with Redux.
Should there be a reducer per module/tab and then combined with combineReducers? Or should there be one reducer for all modules/tabs and their subroutes? Will this mean that there is a nested state tree?

Hope someone has an idea!