Integration of personal calendar with bookings calendar

I am juggling multiple calendars for multiple companies and personal scheduling on multiple platforms. I had hoped by adding ical subscriptions for busy time would reflect inside Bookings availability, but unless I am missing a step here this seems to not be an option.

It would be incredibly useful either inside of bookings or through viewing the availability through subscribed calendars on the Outlook service, to be able to determine busy/free time of all my calendars.