Hi Experts,
I'm working on Apex 20.1.0.00.13 and had a similar requirement too How to display specific tab using Region Display Selector at displaying page?
I've Page 1 where I've Region Display Selection and two tab each of them have been assigned a static ID as DailyV and DailyR. Page 1 also has an page item flag to which I would be using as a flag to flip b/w both tabs.
I've created Dynamic Action event of Change Item type in which I'm passing JS as showed in Diagram

Also, I've Page 2 where I've one bar chart by clicking on which I'm passing this value as V to attribute Flag.
WHen I ran this app and navigate from Page2 to Page1 it doesn't show me desired Tab. But I manually enter a value in Item R or V then appropriate tab is displayed.
Can you please advise if I must change when condition or If I'm missing something. Obviously I would like to hide this item attribute from end user view once everything works fine.
Appreciate your advise.
Cheers, Ajax