Yeah, it's a very handy facility. I tried and learned something new.
When designing layout, we turn to add new Ctrl, copy& paste, and moving things around, resulting in Ctrls not in sensible tab-order. By selecting a group of Ctrls and apply the button, the layout designer will order the Ctrls in a left-to-right-top-to-bottom order so navigate by tabbing will not seem to be random.
Note the selected Ctrls will be removed from the layout and then insert to the very front of the layout after sorting by their position.
Great to know. I used to do it manually with a lot of effort and many rounds of try-and-error.