Once we have added the calendars we see the following view of data:
This shows that as we wanted, the calendars of James, Laura and Roman are now part of this view. But at the moment if we look at the "access from" list we will see that it is empty. This means that no one can currently see this view. To remedy that we need to click on the "add" button.
Now we can choose the group Sales Department.
You will see that the only option available in terms of Access Level is "add" - as mentioned before, this is because GroupCalendars are read only, editing takes place by editing the individual calendars.