When using the event triggers in automations - there is no way to specify an answer from a form as a trigger.
(Nb: You can do this with the ‘forms’ triggers but not ‘events’ triggers).
Eg: I want a trigger for ‘ticket ordered’ + ‘add to mailing list’ = true (this is an answer from a question in the event reg form submitted to buy the ticket).
It could be possible to use a custom field to create a segment and then the trigger is being added to the segment. However custom fields can’t be binary (yet) so I would have to get them to type ‘Yes’ into the field. Bit too scrappy and unreliable for me though.