As far as I know from a friend who is HK base, they don't get group interview. The only thing they had to do was a English test and the normal interview. The first interview was 1-1 and then the second interview it was 2-2-1 interview. He couldn't say how many got the job after the interview as he doesn't know how many people had interviews as it was ongoing.
I didn't pass the interview.
However, if I do decide to reapply, I would be much prepared.