Determine which tab is active from the controller

Good Morning (or afternoon). I have a form that contains several tabs (organized sections) and then an edit button. What I want to do is, EDIT the information based on the active tab (Tombstone/Sales/Dates). How do I pass to the controller the active tab and then redirect to the proper Template?

Template View form

I would add a hidden input per tab section which is called something like

<input type="hidden" name="tab_section_1_open" value="0"/>

and set the value part of that to 1 (via JS) if a certain section is open.

With that you will then know on form submit which section was currently open after the form has been submitted and can react to it.