[@sociality Participant 6 years, 2 months ago]

Hi there I had the same problem and I used this solution that does not use buddypress. The sanitize title I use if for greek so I do not post it here but you should use something for sure.

//This is used to hide the username from the profile url
function tpp_forum_profile_url( $user_id, $old_values) {
	$user = get_user_by( 'ID', $user_id );	
		$display_name = $user->data->display_name;	
	if ( $user ) {
		if ( $user->data->user_status == 0 && $display_name ) {
			$new_user_nicename = tpp_sanitize_title($display_name );
			if ( strlen ( $new_user_nicename ) > 50 ) {
				$new_user_nicename = substr ( $new_user_nicename, 0, 50 );
			}				
			if ( $user->data->user_nicename != $new_user_nicename ) { 
				$args = array(
					'ID'            => $user->ID,
					'user_nicename' => $new_user_nicename
				);
				wp_update_user( $args );
				wp_redirect( get_site_url().'/forums/user/'.$new_user_nicename.'/edit/' ); 
				exit;					
			}
		}
	}
}
add_action( 'profile_update',  'tpp_forum_profile_url', 100, 5 );