JSFiddle - React, Tailwind, and code Playground
by Deepak Manwal
HTML
<select id="main">
<option>all</option>
<option class="first" value="first">first opt</option>
<option class="second" value="second">second opt</option>
<option class="third" value="third">third opt</option>
</select>
<select id="sub_first" class="sub">
<option>sub 1</option>
<option>sub 1</option>
</select>
<select id="sub_second" class="sub">
<option>sub 2</option>
<option>sub 2</option>
</select>
<select id="sub_third" class="sub">
<option>sub 3</option>
<option>sub 3</option>
</select>
JavaScript
$(".sub").hide();
$("#main").change(function() {
var val = $(this).val();
$(".sub").hide();
if( val ) {
$("#sub_" + val).show();
}
})