I see,
but you did not send a *.lss file. So I cannot see your validation.
On the other side you use a non-standard workaround.
Maybe you can improve the validation.
Or you restructure the question.
I can recommend Headers (advisable if nearly each option has suboptions):
Or just split the question (advisable if only a few options have suboptions):
Advantage: The cleanest way. It's standard out of the box.
Regards
Joffm