Misplacement of Laravel Livewire Tenancy File Uploads into Central Storage Instead of Tenant-Specific Storage

I've had exactly the same issue as you've described, I'm using stancl/tenancy in a Filament v3 project (using Livewire v3). What I did was the following:

First, make sure you have enabled universal routes and followed the steps for real-time facades:

https://tenancyforlaravel.com/docs/v3/features/universal-routes https://tenancyforlaravel.com/docs/v3/realtime-facades

The below steps A and B are from here: https://tenancyforlaravel.com/docs/v3/integrations/livewire/

A. In a service provider (AppServiceProvider for me), add the following to the boot() function:

public function boot(): void
{
    // ...

    Livewire::setUpdateRoute(function ($handle) {
        return \Illuminate\Support\Facades\Route::post('/livewire/update', $handle)
            ->middleware(
                'web',
                'universal',
                InitializeTenancyByDomain::class, // or whatever tenancy middleware you use
            );
    });

    FilePreviewController::$middleware = ['web', 'universal', InitializeTenancyByDomain::class];
}

B. In the Livewire config file (which you have to publish yourself in case you haven't done that already) I have modified the middleware field of the temporary_file_upload section to include the tenancy initialization middleware and universal routes:

'temporary_file_upload' => [
// ...
	'middleware' => ['throttle:60,1', 'universal', InitializeTenancyByDomain::class],
// ...
]

C. Then, I had to create a new filesystem tenancy bootstrapper, in which I have copied the contents of FilesystemTenancyBootstrapper (that comes bundled with the stancl/tenancy package) and added the following lines to the bootstrap() function, in order to overwrite the public disk's url property, as I was using (and having issues) with the public disk:

    public function bootstrap(Tenant $tenant)
    {
        foreach ($this->app['config']['tenancy.filesystem.disks'] as $disk) {
            // ...

            if ($disk === 'public') {
                $this->app['config']["filesystems.disks.public.url"] = 'http://'.parse_url(url()->current())['host'].'/tenancy/assets';
            }
        }
    }

You'll have to make sure that you're registering this new filesystem bootstrapper in the tenancy config file, under the 'bootstrappers' section and also don't forget to remove the old one.