Showing Parent Category Name above children in List of Categories Menu Item?

[heavyboots]

Is there a way to do something like this by changing settings? In the example images, North America and Mexico are Parent Category Titles and the thumbnails are child folders. I would embed the images, but that seems to be disabled here, so I've posted Imgur links.

Essentially I want to go from what I currently have (all child categories in a jumble):

https://imgur.com/w83F513.jpg

to this (parent category titles above each set of child categories):

https://imgur.com/9B1R7E5.jpg

Thanks in advance for any help you guys might provide!