If you've shared your calendar with others, you may at time need to review which users or links have access to certain sub-calendars. 

Note that only calendar administrators can access the calendar settings. 

Two ways to review access to sub-calendars 

1: View sub-calendar access 

1. Go to Settings > Calendars.
2. Select the pencil icon next to a sub-calendar.
3. Scroll to the bottom of the screen to the Users With Access section. You will see a list of account-based users and shareable links with access to the sub-calendar:

  
2: View user/link information

1. Go to Settings > Sharing.
2. Each user/link in the Sharing list has a summary of access (on the right), including the number of calendars they can access. 
3. Click the blue Calendars link to see a pop-up of which calendars are included:
   
   
4. Click the Pencil icon to the right of any user or link to modify their access. See here for more.