JSFiddle - React, Tailwind, and code Playground

HTML

<h2>Dropdown 1</h2>
<select id="dp1">
    <option value="Test">Test</option>
    <option value="example">Example</option>
    <option value="test1">test1</option>
    <option value="test2">test2</option>
</select>

<h2>Dropdown 2</h2>
<select id="dp2">
    <option value="Test">Test</option>
    <option value="example">Example2</option>
    <option value="test1">test1</option>
    <option value="test2">test2</option>
</select>

JavaScript

$('#dp1').change(function(){
    if(this.value === 'example'){
        $('#dp2').hide();  
    }else{ // If you want it to show on other values
        $('#dp2').show(); 
    }
});