Allows members to delete their own topic in BuddyPress group forums. I advise you to be very careful with this script as BuddyPress normaly only allows group admin or super admin to delete topics.

bastien-delete-own-topic.php

<?php

/** Beginning of the code to copy in the functions.php of your active theme **/

function bastien_own_topic_delete() {

  
	if( bp_get_the_topic_is_mine() && ( !bp_is_item_admin() || !bp_is_item_mod() || !bp_current_user_can( 'bp_moderate' ) ) ) {
	?>
	<div class="admin-links" style="margin-right:50px!important">
		<a class="confirm" id="topic-delete-link" href="<?php echo wp_nonce_url( bp_get_the_topic_permalink() . 'delete', 'bp_forums_delete_topic' ) ;?>"><?php _e( 'Delete Topic', 'buddypress' ) ;?></a> | 
	</div>
	<?php
	}
		
}

add_action( 'bp_group_forum_topic_meta', 'bastien_own_topic_delete' );

/** End of the code to copy in the functions.php of your active theme **/

?>