BuddyPress.org

Hi
I am using buddypress on my website, and when a user send’s a message its shows the real name of user and not the username, i want it to be username. I did go through the code for messages in bp-messages-template

function bp_message_get_recipient_tabs() {
	$recipients = explode( ' ', bp_get_message_get_recipient_usernames() );
	
	foreach ( $recipients as $recipient ) {
		$user_id = bp_is_username_compatibility_mode() ? bp_core_get_userid( $recipient ) : bp_core_get_userid_from_nicename( $recipient );
		if ( $user_id ) : ?>

			<li id="un-<?php echo esc_attr( $recipient ); ?>" class="friend-tab">
				<span><?php
					echo bp_core_fetch_avatar( array( 'item_id' => $user_id, 'type' => 'thumb', 'width' => 15, 'height' => 15 ) );
					echo bp_core_get_userlink( $user_id );
				?></span>
			</li>

		<?php endif;
	}
}

But this shows it is picking up username and not the real name. Can anyone tell me where to make a change so that it displays the username and not the real name of person.
Thanks!