JSFiddle - React, Tailwind, and code Playground

HTML

<form>
    <select>
        <option onclick="hide('1','2');">Show textbox 1</option>
        <option onclick="show('1','2');">Show all</option>
    </select>
    <br/>
    <input id="1" type="text" value="blah 1" style="display:none;"/>
    <input id="2" type="text" value ="blah 2" style="display:none;"/>
</form>

JavaScript

function hide(a,b){
    document.getElementById(a).style.display='block';
    document.getElementById(b).style.display='none';
}
function show(a,b){
    document.getElementById(a).style.display='block';
    document.getElementById(b).style.display='block';
}