ahteeshamkhan you cannot link multiple stores to the Promo Sliders. As Promo Sliders can be linked to a single Store/Resturant or Item or any custom URL.
Linking multiple stores is possible only in the Store Category Slider.
(Later we have plans to come up with Store Category Slider Page URL, so that URL can be inserted in the Promo Sliders Custom URL and that should work - future plans)
