Product listing in category, group by sub-category

I am using Maximenu with the HikaShop plugin to display a list of products.

I would like the list to be grouped by sub-categories of the selected category, but without the list of categories at the top of the list. I would also like the category titles to be simple, one-line entries.

Something like:

-- Nuts --
Peanuts
Pecans
Cashews
-- Chocolate --
Milk Chocolate
Dark Chocolate

Where Nuts and Chocolate are sub-categories and the others are products.

Is this possible? Where would I go in the configuration, or will I have to modify code?

Thanks!