How do I remove the shared Family calendars from BusyCal?
When you enable iCloud Family Sharing, two shared calendars named "Family" will appear in BusyCal's sidebar. One is an Event calendar and the other is a To Do calendar (the To Do calendar has a checkmark √ next to its name and syncs with the Reminders app on iCloud and iOS). These calendars are automatically created by iCloud and shared with all family members.
You cannot delete these calendars but you can hide them, if you wish, by unsubscribing to them.
To unsubscribe, double-click on the calendar in the left sidebar to show the Calendar Info dialog and click the Unsubscribe button. Then, choose Hide Unsubscribed Calendars from the View menu. The shared Family calendars will continue exist on iCloud and iOS, but they will no longer be displayed in or synced with BusyCal.
Note: If you have a Calendar Group for your To Do calendars, you can drag the Family √ To Do calendar into that Group in BusyCal's sidebar to help with organization.