Affiliate Pro + Affiliate sharing for several sites

We have installed affiliate pro with woocommerce in one site along with affiliate sharing using addthis plugin. It works on the site where it is installed but since we have two sites I would like to know how to extend the affiliate sharing functionality to a second site without having affiliates registering at the second site. The second site can be a subdomain of the main site. Therefore when they share links on the second site using addthis plugin they can get paid on the main site