Can't make accordions with clusters and resources in Filament 4.x

Certainly! In Filament 4.x, clusters are used to group resources in the sidebar. However, if you want to have an accordion-style menu (where clicking the cluster expands to show the resources), you need to ensure a few things:

1. Cluster Class: Make sure your CustomersCluster class extends Filament\Clusters\Cluster and is properly registered.

2. Resource Configuration: Each resource that should appear under the cluster must have the following property set:

   protected static ?string $cluster = CustomersCluster::class;
   

3. Panel Registration: Ensure your cluster is registered in your Filament panel provider (usually in PanelProvider.php):

   use App\Filament\Clusters\CustomersCluster;
   
   public function panel(Panel $panel): Panel
   {
       return $panel
           // other registrations...
           ->clusters([
               CustomersCluster::class,
           ]);
   }
   

4. Sidebar Behavior: Filament 4.x should automatically render clusters as expandable accordions in the sidebar. If you see a "Customers" button that opens a new page instead of expanding, it usually means:

   • The cluster is not registered correctly.
   • The resources are not properly linked to the cluster.
   • You might be using a custom sidebar or have overridden the default navigation.

Check your Cluster class:

namespace App\Filament\Clusters;

use Filament\Clusters\Cluster;

class CustomersCluster extends Cluster
{
    public static function getLabel(): string
    {
        return 'Customers';
    }
}

Check your Resource class:

protected static ?string $cluster = CustomersCluster::class;

Check your PanelProvider:

->clusters([
    \App\Filament\Clusters\CustomersCluster::class,
])

If it still doesn't work:

• Clear your cache: php artisan optimize:clear
• Make sure you are using the latest Filament 4.x beta.
• Check for any custom sidebar overrides.

Summary:
If all of the above are set up, Filament 4.x should display your cluster as an accordion in the sidebar, with the resources nested inside. If you still see a separate "Customers" page, double-check your cluster registration and resource configuration.

Let me know if you need a more specific example or if you can share your cluster and resource code!