Hi Subramanian,
In case if your are using FPM in your scenario, when user changes a tab, the corresponding event can be fetched in PROCESS_EVENT in the component controller which is implemented with if_fpm_ui_building_block interface.(io_event).
In case if are implementing without this interface, specify the empty view name and in the corresponding view DOINIT method write the logic for opening the view as a pop up, which might also be good option.
Regards,
Harsha