As for the Custom Event solution, you need to create a Custom Event using the filtering shown in the screenshots above. But for the Custom Event, from what I tested so far you need a button that “triggers a custom event”. There is a hook like this in the workflows.
When a button is clicked → trigger a custom event → in the custom event you have the filters. I created just one filter when user selects options from all 3 groups. So you would need to create next steps in the workflow for when user uses 2 groups and just 1 group.
