I'd like to assign our French domain (social-ability.fr) to go to our French version of the website. That's working fine. The issue I have is when I wanted to add hidden link, is it possible to do this? i.e. have more than 1 domain/subdomain per language.
Do I need to setup a redirect from social-ability.fr -> hidden link, then register hidden link with WPML? Is there a better way to do this?
it is possible but you need to have 2 different domains, not the same. You need them setup so they show the same website, even without WPML, and both domains working fine.
Then you can set up language per domain as explained in the next docs: