a few proven tips that might be useful to you

1. 大老板 never wants every one in 中老板's team on 中老板's side. To manage 中老板, 大老板 needs some people he can trust under 中老板 so that he knows what's really happening in 中老板's team.
2. 中老板 absolutely hates the idea of someone with 大老板 being inserted into his team. Reasonably he will try to cut your exposure so that you won't have a good reason to directly update 大老板.
3. To your own interest, you need to have direct contact with 大老板 but without being seen by your 中老板. So try your best to find the time that your 中老板 is not there to update your 大老板. But on the other side, make sure that you update your 中老板 before updating 大老板 as you don't want to be hated so much.
4. now you can see that reporting to 小老板 is a horrible idea. 中老板 will say "as you wish" and 大老板 will be disappointed .
5. don't 打小报告 as it won't reflect good on you. Try something you can do, such as , when 大老板 and 中老板 have different opinions on the direction of a project , provide argument to support 大老板. If you pay attention, you will find 大老板 and 中老板 always have different interest.
Hope that helps a little.