How do i break a component asset to sub-component assets

gwaindepy

I understand that Navision has got only two levels when it comes to breaking down assets, there is main asset and component asset. But now i need to break my component asset into sub components as well and so on, so that one asset(e.g a Plant) can have many components(e.g generator) and the components can have their sub components as well(e.g generator fuel pump). May somebody help me on how i can achieve this. thank you