categorizing services in appointments settings

Hi,

I'm trying to use this for a hair salon business. We have about 5 main categories like hair cuts, braids, spa services, etc. Each category has sub items. Is there a way to categorize the services? So for example I can add hair cuts as a category, and then have services like ponytails, mohawks, rollersets? Having the customer select 1 service out of about 30 without a way to sort them is rather messy. Thank you.