3DS XL still doesn't have a second analogue nub, which still annoys a lot of people. But if you really must have a second stick on your handheld, then you can grab the new Circle Pad Pro extension from Nintendo. We've got the first pic below.
The shot comes courtesy of Nintendo Everything, and still looks odd:
The extension can be used for Resident Evil: Revelations, Kid Icarus: Uprising, Monster Hunter 3 Ultimate and Metal Gear Solid: Snake Eater 3D.