photofloh32
Hi
The button is defined in /components/com_community/templates/jomsocial/layouts/register/success.php
<a href="<?php echo $uri; ?>" class="joms-button--primary joms-button--full-small">
<?php echo JText::_('COM_COMMUNITY_BACK_HOME'); ?>
</a>
You can change <?php echo $uri; ?>
with your link, You can also create an override for it in the template folder /html/com_community.
Regards