JSFiddle - React, Tailwind, and code Playground
HTML
<link rel="stylesheet" href="http://silviomoreto.github.io/bootstrap-select/bootstrap-select.min.css">
<script src="http://silviomoreto.github.io/bootstrap-select/bootstrap-select.min.js"></script>
<select class="selectpicker" multiple title="Not changable text" data-count-selected-text="Not changable text">
<option>Mustard</option>
<option>Ketchup</option>
<option>Relish</option>
</select>
<button id="f1">ggg</button>
JavaScript
$('#f1').click(function(){
$('.selectpicker').selectpicker('deselectAll');
});