Hide a Single Event in Google Calendar
To make sure an event or appointment is not visible on a shared calendar in Google Calendar: Note that all other owners of the calendar (i.e., people with whom you share the calendar and who has permission to either Make Changes to Events or Make Changes and Manage Sharing) can still see and edit the event. Everybody else will see “busy” but no event details.
Sharing Options in a Shared Google Calendar
When you share your Google calendar with someone, you can choose how much information they can see about your scheduled events. These options include:
See only free/busy. The person who shares the calendar with this setting can only see whether you are available or busy at a specified time and date.See all event details. This privilege level allows the person sharing the calendar to see all of your events and the details.Make changes to events. With this privilege level, the person with whom you are sharing your calendar can see all of the details to all of the events and edit them.Make changes to events and manage sharing. This is the most comprehensive privilege level. The person with whom you are sharing your calendar can see, change, and share your calendar with anyone they choose.