Hi hejsam,
Yes, I understand! Unfortunately, I have never seen a good quality, shielded male RJ45 to twin female RJ45 socket adapter. Hence, the best option is the male RJ45 to twin female DIN adapter that we discussed already, then you can use an RJ45 to DIN cable to connect from one socket of this adapter to the Beoplay S8:-
You can use a normal DIN to DIN Powerlink from the other socket of the adapter to the first Beolab 6000 and another one between the two rear speakers:-
Location: The cable workshop, England
My B&O Icons: