Hi Justin,

Thanks for your suggestion but currently we do not have the plan yet to implement sub categories in groups / events. Maybe you can submit your idea into our feature voice page http://stackideas.com/voices/easysocial

Thanks again for your feedback and your suggestion.
Have a nice day

Sounds good. It looks like it was added to voices a while back: http://stackideas.com/voices/easysocial/item/455

Thanks.

Thanks Justin