Larian Studios Forums Divinity: Original Sin 2 Divinity - Original Sin 2 - General Inventory Management Needs a Revamp

Another good idea would be that if you click a backpack in your inventory in the trade window, the backpack is instead opened to show the contents to let you better organize things you want to sell into one convenient place.

Additionally, a "trade all" button will be added to the backpack inventory screen only to let you dump the entire contents of the backpack into the trade menu in one shot.