How can I make the down arrow select the next item?

I'm wondering if it's possible to make the down arrow select the next item in the list, rather than the next category.

Currently, when I am searching for something, and I press the down arrow key, it selects the "All" category first, then each category after that on subsequent presses.

What I'm trying to get it to do is select the search result on the right when I press the down arrow, and then each search result under that on subsequent presses.

Currently in order to select the second search result, I have to press the down arrow, then the right arrow, then the down arrow again.

Edit: Just realized the state of this project .-.