hmm are you sure? the thread you linked is for high five, I doubt it would work on classic chronicles.
Also according to the original picture
I see no other custom features other than those two small skillbars, which leads me to believe that it's probably not what you linked, otherwise it would be visible.
So a few months ago a guy appeared on classic club forums and posted a screenshot.
On the screenshot you could see this:
Does anyone here have the files for this extra skillbar(that's marked in red)? Asking on forums didn't help as the guy who posted that disappeared and nobody seemed to have these files for the current chronicle. I'm not sure on which client version we are. We are officially on zaken patch but server is using antharas patch files(according to admins