<link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.0/js/bootstrap.min.js"></script>
<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>
<div class="container">
<div class="row">
<div class="col-sm-3 nav-container">
<div class="form-group">
<select class="form-control nav">
<option value="" selected disabled>seleziona una serie</option>
<option value="serie-0">Vivaro - T180</option>
<option value="serie-1">San Vito al Tgl. - TM10</option>
</select>
</div>
</div>
<div class="col-sm-9">
<div class="select-pane" id="serie-0">SERIE 0</div>
<div class="select-pane" id="serie-1">SERIE 1</div>
</div>
</div>
</div>