How exactly do I create sub-sub-categories? As an example: https://www.speedrun.com/mc As you can see, they have 5 categories, each with other categories like Set seed and random seed, and then they have categories under those categories. How would I be able to do that?

Create a new variable and apply it to the category that you want.

Yea I understand that part, but how would I create another category inside of those sub-categories. Thank you for responding!

it's not nested in that way. every subcategory is just a variable of the highest tab, you just keep adding variables for more layers of subtabs. e.g. the Any% Glitchless category has two variables: Seed Type with the values "Set Seed" and "Random Seed"; and Version Range with the values "Pre 1.9", "1.9-1.15", and "1.16+".

Ahhh, thank you