bbpress display last 5 forum topics

<?php
$show_sep = false;

if ( 'forum' ==  bbp_get_forum_last_active_id() ) {
$breadcrumbs = '<a href="' . bbp_get_forum_permalink( $parent->ID ) . '">' . bbp_get_forum_title( $parent->ID ) . '</a>';
}

if ( $breadcrumbs ) {
?>
<ul class="square-bullets">
<?php
printf( __( '<li>Posted in %2$s ' ),'', $breadcrumbs);
$show_sep = true;
echo '</li>';
echo '</ul>';
}
?>