this is a little BuddyPress trick to hide friends nav and activity friends subnav to members visiting other member profiles. It's a reply to this topic : http://bp-fr.net/groupes/utilisation-configuration-optimisation-de-buddypress/forum/topic/supprimer-longlet-amis-de-la-fiche-dun-membre/

mathieu-hides-member.php

<?php
/**** beginning of the code to copy in the functions.php file of active theme ****/

function mathieu_hides_friends_nav( $nav_items, $nav_items_args ) {
  
	if( is_super_admin() )
		return $nav_items;
	
	if( bp_is_user() && !bp_is_my_profile() )
		return false;
		
	else
		return $nav_items;
}

add_filter( 'bp_get_displayed_user_nav_friends', 'mathieu_hides_friends_nav', 10, 2 );
add_filter( 'bp_get_options_nav_activity-friends', 'mathieu_hides_friends_nav', 10, 2 );

/**** end of the code to copy ****/
?>