How to run custom function after clicking next on a multi page webform
One way to accomplish this task, because the webform module is so complex, is to just use jQuery and attach to that button and node id and run an AJAX query or whatever else you want to do like redirect the user away and then back.

Otherwise you would probably be neck deep in a custom module that extends Webform. In my experience to alter webform modules becomes a major pain and I generally just go another route.