BuddyPress.org

I have added a new tab for profile tab using following code.

add_action('bp_setup_nav', 'mb_bp_profile_menu_posts', 301 );
function mb_bp_profile_menu_posts() {
global $bp;
bp_core_new_nav_item(
	array(
        'name' => 'My Posts',
        'slug' => 'posts', 
        'position' => 11, 
        'default_subnav_slug' => 'published', // We add this submenu item below 
        'screen_function' => 'mb_author_posts'
	)
);
}

I need to show 5 latest posts from the user in this tab. How to do it? (Currently when click the “My Posts” tab it says 404 error.