php – How to add plugin options tabs as submenu items, and give them a current class

I have a custom plugin that is working great. I have set up multiple tabs that include content on each. I have now added each of the tabs as submenu items successfully, but I’m having trouble adding the “current” class to them when on that tab.

Here is my ode:

add_action( 'admin_menu', 'eri_Add_My_Admin_Link' );
function eri_Add_My_Admin_Link() {
    // The 'slug'
    $slug = 'eri-webtools-plugin/includes/admin/eri-admin-page.php';
    
    // Get notification count
    $warning = eriErrorCount();
    $notif = '';
    if ($warning > 0) {
        $notif = '<span class="awaiting-mod">'.$warning.'</span>';
    }
    
    // Add a new top level menu link to the ACP
    add_menu_page(
        'ERI Web Tools', // Title of the page
        $warning ? 'ERI Tools '.$notif : 'ERI Web Tools', // Text to show on the menu link
        'manage_options', // Capability requirement to see the link
        $slug, // The 'slug' - file to display when clicking the link
        '',
        plugins_url( 'eri-webtools-plugin/includes/admin/star15x15.png' ), // The admin menu icon
        4
    );
    
    // Add submenu
    global $submenu;
    $tab_path = '/wp-admin/admin.php?page=eri-webtools-plugin%2Fincludes%2Fadmin%2Feri-admin-page.php&tab=';
    // Welcome
    $permalink1 = '/wp-admin/admin.php?page=eri-webtools-plugin%2Fincludes%2Fadmin%2Feri-admin-page.php';
    $submenu($slug)() = array( 'Welcome', 'manage_options', $permalink1 );
    // Settings
    $permalink2 = $tab_path.'settings';
    $submenu($slug)() = array( 'Settings', 'manage_options', $permalink2 );
    // Debug
    $permalink3 = $tab_path.'debug';
    $submenu($slug)() = array( 'Debug', 'manage_options', $permalink3 );
    
    //call register settings function
    add_action( 'admin_init', 'register_eri_plugin_settings' );
}

Any suggestions?