Bootstrap 4 multi-select dropdown

<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-select/1.13.1/css/bootstrap-select.css" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.bundle.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/bootstrap-select/1.13.1/js/bootstrap-select.min.js"></script>



<select name="category" class="form-control selectpicker"  multiple data-live-search="true" multiple data-selected-text-format="count > 3">
  <option>Mustard</option>
  <option>Ketchup</option>
  <option>Relish</option>
</select>

<script>
$('select').selectpicker();

</script>