[fsatark]

Is there a way to create video "SubCategories"
The structure of the original add-on is

1) 'Animals'
-> 'Crab'
-> 'Alligator'
-> 'Turtle'

2) 'Cars'
-> 'Postal Truck'
-> 'Traffic'
-> 'Traffic Arrows'

etc.

I'm looking for something like this:
1) 'Animals'
-> 1A) 'Wild Animals'
---> 'Lion'
---> 'Tiger'
---> 'Zebra'

-> 1B) 'Domestic Animals'
---> 'Chicken'
---> 'Cat'
---> 'Dog'

-> 1C) 'Sea Animals'
---> 'Dolphin'
---> 'Goldfish'
---> 'Tuna'

Is possible to create something like this, modifying the main code?
Please advice. Thank you.