<script src="https://cdnjs.cloudflare.com/ajax/libs/Sortable/1.8.3/Sortable.min.js"></script>
<div id="nestedDemo" class="list-group col nested-sortable">
  <div class="list-group-item nested-1">Item 1.1
    <div class="list-group nested-sortable">
      <div class="list-group-item nested-2">Item 2.1</div>
      <div class="list-group-item nested-2">Item 2.2
        <div class="list-group nested-sortable">
          <div class="list-group-item nested-3">Item 3.1</div>
          <div class="list-group-item nested-3">Item 3.2</div>
          <div class="list-group-item nested-3">Item 3.3</div>
          <div class="list-group-item nested-3">Item 3.4</div>
          <div class="list-group nested-sortable">
      <div class="list-group-item nested-2">Item 2.1</div>
      <div class="list-group-item nested-2">Item 2.2
        <div class="list-group nested-sortable">
          <div class="list-group-item nested-3">Item 3.1</div>
          <div class="list-group-item nested-3">Item 3.2</div>
          <div class="list-group-item nested-3">Item 3.3</div>
          <div class="list-group-item nested-3">Item 3.4</div>
          <div class="list-group nested-sortable">
      <div class="list-group-item nested-2">Item 2.1</div>
      <div class="list-group-item nested-2">Item 2.2
        <div class="list-group nested-sortable">
          <div class="list-group-item nested-3">Item 3.1</div>
          <div class="list-group-item nested-3">Item 3.2</div>
          <div class="list-group-item nested-3">Item 3.3</div>
          <div class="list-group-item nested-3">Item 3.4</div>
        </div>
      </div>
      <div class="list-group-item nested-2">Item 2.3</div>
      <div class="list-group-item nested-2">Item 2.4</div>
    </div>
        </div>
      </div>
      <div class="list-group-item nested-2">Item 2.3</div>
      <div class="list-group-item nested-2">Item 2.4</div>
    </div>
        </div>
      </div>
      <div class="list-group-item nested-2">Item 2.3</div>
      <div class="list-group-item nested-2">Item 2.4</div>
    </div>
  </div>
  <div class="list-group-item nested-1">Item 1.2</div>
  <div class="list-group-item nested-1">Item 1.3</div>
  <div class="list-group-item nested-1">Item 1.4
    <div class="list-group nested-sortable">
      <div class="list-group-item nested-2">Item 2.1</div>
      <div class="list-group-item nested-2">Item 2.2</div>
      <div class="list-group-item nested-2">Item 2.3</div>
      <div class="list-group-item nested-2">Item 2.4</div>
    </div>
  </div>
  <div class="list-group-item nested-1">Item 1.5</div>
</div>