You may optionally set a PHP callback here to manipulate the finder with additional criteria, or override existing criteria.<br />
<br />
Callback arguments:
<ol>
	<li>
		<code>\XF\Entity\MemberStat $memberStat</code>
		<br />
		This member stat entity.
	</li>
	<li>
		<code>\XF\Finder\User $finder</code>
		<br />
		The User finder set up with the criteria/order settings already specified above.
	</li>
</ol>
The callback should either return an array or nothing at all. If nothing is returned, the results will be formatted automatically. Example array:<br />
<br />
<code>return [$user->user_id => \XF::language()->numberFormat($value)];</code>