Can't See Calendar Groups on Calendar
To see multiple calendar groups on your calendar, you must set your calendar view to daily. If your calendar view is set to weekly or monthly, it will not show the individual calendar groups, just all the appointments. You can change the calendar view by selecting a view option from the upper right-hand corner, while viewing the calendar (see image below).
You can also set your default calendar view to day, week or month from the settings page (see image below).