JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tr id="tr_level_1"><td>1</td></tr>
    <tr id="tr_level_2"><td>2</td></tr>
    <tr id="tr_level_3"><td>3</td></tr>
    <tr id="tr_level_4"><td>4</td></tr>
    <tr id="tr_level_5"><td>5</td></tr>
</table>

JavaScript

var levels = 3;
var $trs = $("table tr");
var currentLevels = $trs.length;
if (currentLevels > levels) {
    $trs.filter(":gt(" + (levels - 1) + ")").remove();
} else if (currentLevels < levels) {
    var t = "";
    for (i = (currentLevels + 1); i <= levels; i++) {
        t += '<tr id="tr_level_' + i + '"><td>' + i + '</td></tr>';
    }
    $trs.parent().after(t);
}