Syncing only filtered calendar items

Is there a way only to sync just the calendars I have filtered?
I want to be able to only export the YW activities to this calendar. When I first tried it exported everything I was subscribed to not just what was currently filtered. Then I tried unsubscribing to everything else and it worked.
I personally want to know about other ward activities (primary, scouts, etc.) for myself and my family.
Do I have to unsubscribe to everything else each time I want to create a calendar for the young women and their families?

No, as explained in the NOTE in About syncing, the sync process synchronizes all subscribed calendars. That makes sense, since sync is something that happens regularly over time, but showing and hiding calendars in the Calendar view is something that you may do off and on just to focus on a particular calendar or set of calendars. In general, it would not be desirable to have the sync be affected by something that changes as often as which calendars are visible at any given time.

I certainly can understand your desire to export just one calendar, but given the current functionality, you've already hit on the only reasonable way to accomplish the task: Unsubscribe to the other calendars, export (you can Export an iCal file), then subscribe again to all the calendars you want.