Hi James, thanks for reaching out!
Sorry, but I’m afraid that events do not support groups in that way. The Events Calendar does employ WordPress’ default user roles to set access to viewing, editing, and publishing events in the admin area, but assigning full groups to an event and setting notifications is not a support feature at this time.
That said, there may very well be other plugins that offer notifications that can be applied to The Events Calendar. For example, this one looks promising, though I haven’t tested it personally.
Does this help answer your question? Please let me know. 🙂
Cheers,
Geoff