Create a custom display order in the main menu

I have main menu which displays two types of links: CPT and Subcategory. I create the menu with a custom request: I retrieve the Custom Post Type then the sub-categories of the main category in Alphabetical order :

Category A: - Product a - Product b - sub category a - sub category b ... 

But, my client wants a custom display example:

Category A: sub category a - Product b - Product a - sub category b ... 

I thought about creating a Drag Drop solution … but how to implement it