You need CB Content Module, not the bot as the bot is only designed and tested for Joomla articles, then create a new module and add your substitution to it. You need to have the field set to be Ajax on profile view. You can find substitution usage information in the below tutorial.
www.joomlapolis.com/support/tutorials/107-use-cases/18353-using-substitutions-throughout-cb
(Did I mention I really think some simple user documents for each plug in might be handy!)
I agree, we need to improve on our documentation and we're working to do just that. We're also looking into better ways to deliver the documentation. We've numerous plans to improve this that we've discussed internally. More will come after CB 2.0, but for now CB 2.0 is our priority.