Best practices for implementing a multi-level Option Menu on Android?

Question

I'm currently working on a port of an iPhone app into an Android. The iPhone app has a custom global navigation menu at the bottom of the screen, and when bringing this over to Android, it was suggested to replace this custom menu with the generic Option Menu (invoked via the option key on the device) to give it a more native Android look and feel.

The issue is that the menu itself has several layers (e.g. Three main option like A, B, C, and sub-options like A1, A2, A3). I've looked around but have not seen this sort of multi-level option menu on Android apps, so am looking for some guidelines on how this may be best achieved.

I've seen some questions on customizing the Option Menu such as this one; Android: customize application's menu (e.g background color); and they seem to suggest that the native framework doesn't support many options.

Should I be looking at a bit of hacking into the option menu (is this a good idea?), or looking at some other approach to modifying the app flow? Trying to understand what would be the best way to maintain a consistent user experience on Android, while reducing the level of variation from the iPhone app.

Thanks!