Tabbed UI Panel - On Click Event for User flow

Tabbed UI Panel - On Click Event for User flow

I am designing a User Flow for a Web Application, which consists of about 50 .. 100 UI pages. Some of those UI pages are containing a Tabbed Panel. 

When a user clicks on a TAB of such a Tabbed UI Panel, I need to modify some data of the related TAB based on other data of the main UI Page. Therefore I need to know where to implement the action and validation script of a Tabbed UI Panel