In the bottom left hand corner click the Calendar icon
From the Ribbon menu under the Home tab, at the top of the screen click Add Calendar, then Open Shared Calendar
Enter Staff Calendar into the Name Box and click OK
You should now see Staff Calendar under your Shared Calendars on the left-hand side.
On the Office 365 portal click on the waffle icon on the top left and corner
Click All Apps
Click on Import Calendar
Select From Directory and under Add calendar from directory type in Staff Calendar it should resolve to an email below. Select this and click on Add.
You should now see the calendar appear for you on the left-hand side.