Hello,
You can move it by editing this file :
../components/com_easysocial/themes/wireframe/events/default/sidebar.php. Here is the code that render categories:
http://take.ms/cVcOV . However, it is not as simple as move it up and down. When moving this div, it must be wrapped by <?php if ($browseView) { ?><?php } ?> .
<?php if ($browseView) { ?>
<div class="es-side-widget">
<?php echo $this->html('widget.title', 'COM_EASYSOCIAL_EVENTS_CATEGORIES_SIDEBAR_TITLE'); ?>
<div class="es-side-widget__bd">
<?php echo $this->html('cluster.categoriesSidebar', SOCIAL_TYPE_EVENT, $activeCategory) ?>
</div>
</div>
<?php } ?>
Hope this helps.