<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>