JSFiddle - React, Tailwind, and code Playground
HTML
<select id="my_select">
<option value="a">a</option>
<option value="b" selected="selected">b</option>
<option value="c">c</option>
</select>
<div id="reset">
reset
</div>
JavaScript
var previousValue = "";
$("#my_select").on("focus",function(){
previousValue = $(this).val();
});
$("#reset").on("click", function () {
$("#my_select").val(previousValue);
});