Today I found one unique tutorial on how to make several sidebars and assign their contents to separate pages in the form of a drop-down list.. A bit confusing but I think, in practice will be clearer.

Step One Adding Sidebars

Open the function.php file in the theme folder and add the code there to create several sidebars in a loop:

    $dynamic_widget_areas = array(
                /* rename or create new dynamic sidebars */
                "Sidebar 01",
                "Sidebar 02",
                "Sidebar 03",
                "Sidebar 04",
                "Sidebar 05",
                "Sidebar 06",
                "Sidebar 07",
                "Search Template",
                );
if ( function_exists('register_sidebar') ) {
    foreach ($dynamic_widget_areas as $widget_area_name) {
        register_sidebar(array(
           'name'=> $widget_area_name,
           'before_widget' => '
',
           'after_widget' => '
',
           'before_title' => '
',
           'after_title' => '
',
        ));
    }
}
        add_action("admin_init", "sidebar_init");
        add_action('save_post', 'save_sidebar_link');
        function sidebar_init(){
                add_meta_box("sidebar_meta", "Sidebar Selection", "sidebar_link", "page", "side", "default");
        }
        function sidebar_link(){
                global $post, $dynamic_widget_areas;
                $custom  = get_post_custom($post->ID);
                $link    = $custom["_sidebar"][0];
        ?>

        ';
        echo 'Select Sidebar';
        echo '-----------------------';
        foreach ( $dynamic_widget_areas as $list ){
                    if($link == $list){
                      echo ''.$list.'';
                        }else{
                      echo ''.$list.'';
                        }
                }
        echo '
';
        ?>

Select sidebar to use on this page.
ID;}
        update_post_meta($post->ID, "_sidebar", $_POST["link"]);
}
add_action('admin_head', 'sidebar_css');
function sidebar_css() {
        echo'
        
        ';
}

In step two, we add an area to display the sidebar.

I have added this code to the file page.php before posting comments.

ID);
           $link    = $custom["_sidebar"][0];
        if($link != ''){
            echo '
';
                if ( !function_exists('dynamic_sidebar') || !dynamic_sidebar($link) ) :
                endif;
            echo '
';
        }
?>

Externally, in the widget section, after pasting the code, everything will look like this:

After we insert the widget into one of the areas, you need to go to any page or create a new one and specify it in the drop-down list, what sidebar will be displayed on it.

Also in the settings menu there will be a new item Sidebar Selection Which one, when not needed, can be turned off.