Make at least one checkbox "required" in multiple groups on Marketo form.

Thanks Sanford for your reply, I really appreciate it.

However, the form is still submit-able when one checkbox is selected from only one section. It shouldn't be submit-able until at least one check box is selected from other two section. Also, I need to add another rule that if "Unsubscribe me from everything" checkbox is selected at the bottom. The form has to be submit-able with everything else unchecked.

info.hrowen.co.uk/Preference-Centre-2019-LP.html

var checkboxGroups = [
{
  fieldNames: ["selectDeselectChannels", "Opt_in_Email__c", "Opt_in_Mail__c", "Opt_in_Phone__c", "Opt_in_SMS__c" ],
  minChecked: 1,
  maxChecked: Infinity,
  minMessage: "You must check at least one box in each group!"
},
{
  fieldNames: ["selectDeselectContent", "Opt_in_Accessories__c", "Opt_in_Events__c", "Opt_in_MOT_Reminders__c", "Opt_in_News__c", "Opt_in_Offers__c", "Opt_in_Parts__c", "Opt_in_Sales__c", "Opt_in_Service__c", "Opt_in_Service_Reminders__c", "Opt_in_Warranty_Reminders__c" ],
  minChecked: 1,
  maxChecked: Infinity,
  minMessage: "You must check at least one box in each group!"
},	
{
  fieldNames: ["selectDeselectBrand", "Opt_in_Aston_Martin__c", "Opt_in_Audi__c", "Opt_in_BAC__c", "Opt_in_Bentley__c", "Opt_in_Bugatti__c", "Opt_in_Ferrari__c", "Opt_in_Lamborghini__c", "Opt_in_Lotus__c", "Opt_in_HROwen_Bodytechnics__c", "Opt_in_HROwen_Group__c", "Opt_in_HROwen_Insurance_Services__c", "Opt_in_HROwen_Specialist_Cars__c", "Opt_in_Maserati__c", "Puritalia__c_contact", "Rimac__c_contact", "Opt_in_Rolls_Royce__c" ],
  minChecked: 1,
  maxChecked: Infinity,
  minMessage: "You must check at least one box in each group!"
}
];		

// --- no need to edit anything below this line! --

MktoForms2.whenReady(function(form) {
	var formEl = form.getFormElem()[0],
		arrayFrom = getSelection.call.bind([].slice);

	// in real-time, when the max checked is reached, disable remaining 'boxes in the group
	checkboxGroups.forEach(function(group) {
		var groupEls = formEl.querySelectorAll("#" + group.fieldNames.join(",#"));
		arrayFrom(groupEls).forEach(function(el) {
			el.addEventListener("click", function(e) {
				var numChecked = arrayFrom(groupEls).filter(function(itm) {
					return itm.checked;
				}).length;
				arrayFrom(groupEls).forEach(function(el) {
					el.disabled = numChecked == group.maxChecked && !el.checked;
				});
			});
		});
	});

	// check minimum during validation
	form.onValidate(function(nativeValid) {
		if (!nativeValid) return;

		checkboxGroups.forEach( function(group) {
			form.submittable(false);
			var groupEls = formEl.querySelectorAll("#" + group.fieldNames.join(",#")),
				numChecked = arrayFrom(groupEls).filter(function(itm) {
					return itm.checked;
				}).length;
			if (numChecked < group.minChecked) {
				form.showErrorMessage(
					group.minMessage,
					MktoForms2.$(groupEls[groupEls.length - 1])
				);
			} else {
				form.submittable(true);
			}
		});
	});
});