Who can see the events?
Events are by default only visible to those invited but the administrator can chose if the event should be visible for all group members. This can be set when the event is created or by editing it afterwards. The administrator can also edit the groups default event visibility setting inside group settings (the three dots in the menu inside the group).
Members who’s not invited can see these events by going into the group overview. (On the Home page they can only see the events they are invited to) They can also send a message to the host and comment on the event.