In order to access your sub-calendar, you will need to subscribe to the iCal address, which is configured from Gmail. 

1. Open up your Google account and navigate to your Calendar 

1. Click on the three dots to the right of your calendar name, so that you can access the settings 

1. Select one of your sub calendars that you want to bring into Zoho 

1. From the main window, scroll down to the near bottom and look to the Hidden iCal link.  Click on the copy link button on the right hand side.  

1. Move over to Zoho Mail 

1. Click on the Settings option 

1. Then choose the Calendar settings 

1. Navigate to the Subscribe section and click on the Web URL option 

1. In the text box, paste in the iCal Calendar link 

1. Click on the Subscribe button