JSFiddle - React, Tailwind, and code Playground
HTML
<div class="form-group">
<select class="ui fluid search dropdown" id="Severidade" multiple="" name="Severidade" onchange="Filtro()" style="width: 100%"><option value="">Severidade</option>
<option>MEDIA</option>
<option>ALTA</option>
<option>BAIXA</option>
<option>CRITICA</option>
</select>
</div>
JavaScript
$("#Severidade").blur(function(){
var array=new array();
array.push("a","b","c");
alert("OK");
});