Display a different field as profile title in Kunena posts

Hello, wondering if you could please point me in the right direction on how to adjust the profile display in Kunena posts - right now, one can choose the user's name or username to display by the avatar. I'd like to have a different CB field (Screen Name) as for privacy reasons I don't want to reveal the users' real names or usernames.
I realize this is a Kunena question, but it's hard to get a response on their forum, plus you, guys, use Kunena, and are the gurus on CB+Kunena so I thought maybe you can give me a hint which file I should look at and/or how to alter it.

Thanks a bunch.

You can override the Kunena sidebar from within CB Forums > Parameters > Sidebar. Select "Kunena 3.x" for "Model" if you don't see the Sidebar tab. It supports HTML and substitutions so you can have it output whatever you like. See the below on how to use substitutions.

www.joomlapolis.com/documentation/279-community-builder/tutorials/18353-using-substitutions-throughout-cb