I have a select custom field for 'Accommodation' showing the options available for participants in events' registration form. To simplify, lets say there are 10 different accommodation options, 'option 1' until 'option 10'. It gets complicated when each of the different events (around 100 different events) have a different subset of those options, and not all 10 options are available for each event. So event A has options 1,2,3, event B has 2,3,5,7, and event C has all 10 options available.
I created a custom field for each subset of options, but came to a point of having almost 20 different custom fields called accommodation, and then trying to draw up a report of all participants from all events, showing which accommodation option they chose - is just a big mess with 20 custom fields that do not intersect.
My question is how to have only one custom field with all 10 options, but then to somehow specify for each event which out of the 10 options should be displayed and available for choice, for that particular event.