By default, Events inherit permissions from the calendar. However, permissions may be varied on a per event basis.
Edit
To configure permissions for an event go to Administration -> Apps -> Modules -> Events.
1. Select the appropriate instance and either select the required event or Add a new event.
2. Select Permissions. The following view will be presented:
3. Edit/configure:
Filter Groups
Select unassigned to add permissions for additional groups.
Note: read permission allows the group to view the event, write allows the group to edit the details of the event.
Disinherit
Select Disinherit in order to remove previously assigned permissions.
4. Click Save and then Finished.