A reply to one of my blog's comment. The goal is to restrict the content to a BuddyPress member and to run nested shortcode. Example of use : [user_restrict user_id="3"][bc_groups][/user_restrict]

user_restrict.php

<?php
/*
Restricting content to the user_id
Requires BuddyPress 1.7 & Bowe Codes 2.0.1
*/
class Restrict_Content_User_Shortcode{
	
	function __construct() {
		$this->setup_filters();
	}
	
	function setup_filters() {
		add_filter( 'bowe_codes_shortcodes', array( $this, 'register' ), 10, 1 );
		add_filter( 'bowe_codes_shortcodes_settings', array( $this, 'settings' ), 10, 1);
	}
	
	function register( $shortcodes = array() ) {
		$shortcodes['user_restrict'] = array( $this, 'display_restricted' );
		
		return $shortcodes;
	}
	
	/* 
	to make this work, you'll need to close manually the shortcode in wp_editor 
	eg : [user_restrict user_id="2"]the content to restrict[/user_restrict]
	*/
	function display_restricted( $atts = '', $content = '' ) {
		$restricted = false;
		
		$defaults = array( 
			'user_id'     => false,
		);
						
		$r = wp_parse_args( $atts, $defaults );
		extract($r);
		
		if( empty( $content ) )
			return false;
		
		/* adding a do_shortcode( $content ) will allow to make the shortcodes in $content to be interpreted*/
		if( ( ! empty( $user_id ) && bp_loggedin_user_id() == $user_id ) || is_super_admin() )
			$restricted = '<div id="restricted">'.do_shortcode( $content ).'</div>';
		
		else
			$restricted = false;
		
		return $restricted;
	}
	
	function settings( $settings = array() ) {
		
		 $settings['user_restrict'] = array( 
				'attributes' => array(
					array( 
						'id'       => 'user_id', 
						'type'     => 'int', 
						'default'  => 0, 
						'required' => true, 
						'caption'  => __( 'user id to allow the content for' ) 
					)
				),
				'description' => __( 'Restrict content to a user', 'bowe-codes' )
		);
		
		return $settings;
	}
}
 
function restrict_content_user() {
	return new Restrict_Content_User_Shortcode();
}
 
add_action( 'bowe_codes_ready', 'restrict_content_user' );