I have one BU in MC used by two distinct types of business.  One type is B2C and they need a unique preference center that will be combined with other B2C brands.   Another type is B2B and they are not combined with B2C or other B2B brands.  So, how can I set up my processes so that B2C related emails go to the B2C preference center and the B2B emails go to the B2B preference center.   Currently, I'm using the Setup/Account Settings section to add the %%profile_center_url%% to every commercial email sent.  I currently have %%profile_center_url%% set for the B2C center.  How can I set up my MC BU instance or processes so that B2C emails can go to B2C preference center and b2B emails can drive to B2B preference center?