A student can participate maximum 4 program. But if selected program 1 as song, then when selecting program 2 it shouldn’t load song(already selected in P1) and need to load only unselected items
in order to create a sequence of conditional dropdowns, where the first lists all the available courses, the second one lists all but the one that has been chosen in the first one, and so on, you could create each dropdown as an Enum, and to use the Valid_if condition to list only the courses that you want the user to be able to select at every stage.
for instance, for the first choice from the course list, you could have something like:
I’m not sure what you mean but, if this is a new question, please open a new ticket and add a reference to me like this @Ubada . Also, please elaborate on what you mean by the problem with the fourth group.