$('.custom-menu-primary ul li > a > .menu-item-text').each(function () {
  if ($(this).html().indexOf('<br>') != -1) {
    var title = $(this).html().split('<br>')[0];
    var desc = $(this).html().split('<br>')[1];
    if (title == undefined) {
      var titleText = '';
    } else {
      var titleText = '<span class="menu-text">' + title + '</span>';
    }
    if (desc == undefined) {
      var descText = '';
    } else {
      var descText = '<span class="menu-desc">' + desc + '</span>';
    }
    var finalText = titleText + descText;
    $(this).html(finalText);
  }
});