Sorry for the late reply. New topics are no longer indicated on the plugin page.
You could make this change manually.
Open this file: buddypress-simple-events\inc\pp-events-widget.php
Find this code:
<?php while ( $wp_query->have_posts() ) : $wp_query->the_post(); ?>
<li><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></li>
<?php endwhile; ?>
Change it to something like this:
<?php while ( $wp_query->have_posts() ) : $wp_query->the_post(); ?>
<?php $date = get_post_meta( get_the_ID(), 'event-date', true ); ?>
<li><a href="<?php the_permalink(); ?>"><?php the_title(); ?><br/><?php echo $date; ?></a></li>
<?php endwhile; ?>