<li class="dropdown">
         <a rel="nofollow" href="#" class="dropdown-toggle" data-toggle="dropdown">Dropdown            

         <b class="caret"></b></a>
         <ul class="dropdown-menu">
           <li><a rel="nofollow" href="#"><form role="form">
<div class="form-group">
  <label for="sel1">Select list (select one):</label>
  <select class="form-control" id="sel1">
    <option>1</option>
    <option>2</option>
    <option>3</option>
    <option>4</option>
  </select>
  <br>
  <label for="sel2">Mutiple select list (hold shift to select more than one):</label>
  <select multiple class="form-control" id="sel2">
    <option>1</option>
    <option>2</option>
    <option>3</option>
    <option>4</option>
    <option>5</option>
  </select>
</div>