As the other poster noted, I am fairly confident that the regional piece is not for the United Club (not to say it can't be in the future). The image OP shares is the manage subscriptions page, which is where they list all the subscriptions one is enrolled with (e.g. economy plus & baggage).

Baggage & Economy Plus is based on a region, hence when one enrolls in a baggage or E+ subscription, there will be that column "region" filled with what one is enrolled with.

"Region: Select the geographic region where you want to be able to use your subscription."