Referral system issue

Why did Brave change the referral system? now in group 5 the countries of the other groups also appear, for example the United States is group 1 and it also appears in group 5 with a ¿(90)? what does that mean? How will we know if a referral enters which group? for example I get 10 referrals between the United States, Europe and Japan, as I will know if Brave would pay me the corresponding or only 1$ per referral? Please explain this @steeven