You may need to have an appointment slot and need more than one user to be engaged in the sessions.
- Calendar Web Interface with the Appointment Slots feature.
- Go to Calendar.
- At the top-left click Create > Appointment Slots.
- Set the days, schedule and slots duration.
- Click Save.
- Find the Appointment Slots in your calendar events and click the event.
- Click the pen icon to Edit, in the resulting page you can add more users under Guests, on the right.
If the user already uses the new Appointment Schedule feature, they need to use Appointment slots instead.
- In Calendar click the gear icon at the top-right and go to Settings.
- Scroll down and at the bottom, uncheck Create appointment schedules instead of appointment slots.
The appointment schedule feature does not have an option to add guests, users may want to go back to the Appointment Slot feature instead.