bp_xprofile_sync_wp_profile( int $user_id, array $posted_field_ids, bool $errors, array $old_values, array $new_values )

function bp_xprofile_sync_wp_profile( $user_id, $posted_field_ids, $errors, $old_values, $new_values ) {

	if ( ! empty( $errors ) ) {
		return;
	}

	foreach ( $new_values as $field_id => $new_value ) {

		// Get First, Last and Nickname field id from DB.
		$firstname_id = bp_xprofile_firstname_field_id();
		$lastname_id  = bp_xprofile_lastname_field_id();
		$nickname_id  = bp_xprofile_nickname_field_id();

		if ( ! $field_id || $field_id == $firstname_id ) {
			bp_update_user_meta( $user_id, 'first_name', $new_value['value'] );
		}

		if ( ! $field_id || $field_id == $lastname_id ) {
			bp_update_user_meta( $user_id, 'last_name', $new_value['value'] );
		}

		if ( ! $field_id || $field_id == $nickname_id ) {
			bp_update_user_meta( $user_id, 'nickname', $new_value['value'] );
		}

	}

	bp_xprofile_update_display_name( $user_id );
}