With calendar smart lists it is possible to filter for appointments of a specific category or appointments owned by a certain Daylite user for instance.
All appointments of a defined time period will be exported by the Calendar Assistant from ProductivityTools. If you don't specify a time frame, the appointments from the past 5 years up to 5 years to the future are exported.
Please take a look at this article to learn how to set up the calendar export:
🎬 How do I export a Daylite calendar using ProductivityTools?