[Dilettante_Pro]

Не совсем понял, но

<div class="block1">
   <div class="block2_1">
   </div>
   <div class="block2_2">
      2_2_1
      <div class="block1">
         <div class="block2_1">
         </div>
         <div class="block2_2">
            2_2_2
            <div class="block1">
               <div class="block2_1">
               </div>
               <div class="block2_2">
               2_2_3
               </div>
           </div>
         </div>
      </div>
   </div>
</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<script>
var reverseBlock = $(".block1").get().reverse();
$(reverseBlock).each(function() {
   var  data2 = $(this).find('.block2_2').text();
   alert(data2);
   $(this).replaceWith('<div></div>');
});
</script>