Buddypress / Buddyboss exclude users from messaging & mention

functions.php

//array of restricted user IDs
function bp_restricted_user_list(){
	// These user's won't be able to receive the messages.
	$restricted_user_ids = array( 102, 115, 220, 225 ); //Change these values to valid user IDs
	
	return $restricted_user_ids;
}

/**
 * Is user restricted from receiving message.
 *
 * @param int $user_id user id.
 *
 * @return bool
 */
function buddydev_is_user_restricted( $user_id ) {
	$restricted_user_ids = bp_restricted_user_list();

	return in_array( $user_id, $restricted_user_ids );
}

/**
 * Hide public message button if needed.
 *
 * @param array $r button args.
 *
 * @return array
 */
function buddydev_hide_public_button( $r ) {
	if ( bp_is_user() && buddydev_is_user_restricted( bp_displayed_user_id() ) ) {
		$r = array();
	}

	return $r;

}

add_filter( 'bp_get_send_public_message_button', 'buddydev_hide_public_button' );


/**
 * Hide private message button if needed.
 *
 * @param array $r args.
 *
 * @return array
 */
function buddydev_hide_private_button( $r ) {

	if ( bp_is_user() && buddydev_is_user_restricted( bp_displayed_user_id() ) ) {
		$r = array();
	}

	return $r;
}
add_filter( 'bp_get_send_message_button_args', 'buddydev_hide_private_button' );


/*---- Exclude From Mention search -------*/
function exclude_from_buddypress_auto_complete( $args ) {
    $args['exclude'] = bp_restricted_user_list();
	
	return $args;
}
add_filter( 'bp_members_suggestions_query_args', 'exclude_from_buddypress_auto_complete' );