v1.14.0-beta3
https://github.com/snapappointments/bootstrap-select/releases/tag/v1.14.0-beta3

Head:
<link rel="stylesheet" type="text/css" href="./bootstrap-select.min.css" />
Body:
 <select class="selectpicker" multiple aria-label="size 3 select example">
    <option value="1">One</option>
    <option value="2">Two</option>
    <option value="3">Three</option>
    <option value="4">Four</option>
  </select>



<script  src="./bootstrap-select.min.js" type="text/javascript" ></script>