Best practice for multi-level menu in iOS / iPad

I'm designing navigation for standard landscape/split view in iPad and the idea is to make the left side menu a multilevel one, so the user could compare data values on the right side between different levels. Is there any savy way to show such multilevel menu or am I doomed to picker or drill downs? Also if you know of any such component already available online I would very much appreciate the link as it could speed up dev team work too.