Even if you do, though, you definitely shouldn't need to reference any part of the higher-level driver from the lower-level one. I.e. you shouldn't need this member at any point. What are you doing with it?
I understand. Unfortunately, in this case, the bthenum minidriver is actually doing a decent bit of heavy lifting, including making unix calls, and handling all device-specific IOCTLs (as opposed to winebth.sys, which handles radio specific IOCTLs). I now realize that's probably the incorrect approach, as all of these IOCTLs are sent to the _radio_ HANDLE.
In its current state, bthenum is just a way to organize the bluetooth driver code into two files, and most of the code should likely be in the winebth.sys driver. I'll work on re-organizing this when the device related MR are introduced.