I'm looking to build two journeys, A and B. Inside A, I'd like to create a split where I check if user entered B between when they entered A and now. If they have, I need to check that their entry event for B had a particular property (e.g.
amount was more than $500). If the check fails, I want to exit the user from A. Each journey is initiated by API call to /interaction/v1/events.
I'm relatively new to SFMC, but I understand that the journey entry-event tables are just data extensions, so it seems like it should be possible to do this kind of cross-referencing, but I can't figure out how. Is this even possible? If so, how can I go about it?