Not familiar with CAN Hacker, but if you are connected to bmw--device with CTC..and have a splitter cable and another device(ctc-in CAN hacker mode?) I see no reason why you would not see data.
Don`t think you can run 2 devices with one interface
I believe Vector/softing makes wares to do this.
Could depend on the year and country also, seems Bmw only allowed obd2 protocols for some years on usa cars--thru obd 2 socket. The 20 pin socket had everything on it.
But in jbe mode you are bench testing/sorting your controller?
This is Probably way over My Head..just a layman here, but though I would respond.
Regards,
D