JSFiddle - React, Tailwind, and code Playground
HTML
<table id='my_tbl'>
<tbody>
<tr class='department'>
<td>...</td><td>...</td>
</tr>
<tr>
<td>..</td><td>..</td>
</tr>
<tr>
<td>..</td><td>..</td>
</tr>
<tr>
<td>..</td><td>..</td>
</tr>
<tr>
<td>..</td><td>..</td>
</tr>
<tr class='departmentTotals'>
<td>...</td><td>...</td>
</tr>
</tbody>
</table>
JavaScript
$('.department').click(function(){
$(this).nextUntil('.departmentTotals').toggle();
})