Quick answer: You can reorder aisles in your shopping list by using the Reorder aisles option in the list’s menu.
Steps to reorder aisles
Open Shopping list and select the list you want to edit.
Tap the More menu (three horizontal dots) - either in the top right corner or on the floating icon in the bottom left corner.
Tap Reorder aisles.
Hold and drag the horizontal three-line icon beside each aisle to move it up or down.
Tap Save to confirm your new order.
Tap Reset (top right corner) to restore the default order if needed.