Place chicken breast in the instant pot on a trivet, and add a cup of water. Close the lid, and seal the pressure valve. Pressure cook on high for eight minutes.
Half the rolls with a knife, and place bottoms of rolls in a 9 x 9-inch baking pan. Spread shredded BBQ chicken across the rolls, top with sliced onions and pickles. Then top with the other half of the bun.
Broil sliders on high for 90 seconds (or less depending on your oven. Keep a close on to prevent burning.).