jQuery Chosen: how to select 1 option value and remove the same one in another select-menu?

Answer 1

Since you are modifying the option which is selected in the first dropdown the previous options which were disabled are not enabled again.

You need to first enable all the options and then disable only the selected option. Try this

$('.chzn-select').trigger("liszt:updated");
$('.chzn-select').chosen().change( function() {
    var selectedValue = $(this).find('option:selected').val();
    var $options = $(this).parent().find('option').attr('disabled', false);
    $options.filter('option[value="'+ selectedValue +'"]:not(:selected)')
    .attr('disabled', true);
});