Get Form value inside Tabs

Tabs\Tab::make('Erinnerungen')
    ->schema([
      Select::make('assigned')
          ->label(__('Assigned'))
          ->multiple()
          ->live()
          ->afterStateUpdated(function (\Filament\Forms\Set $set, $state) {
                $set('user_group', null);
                $set('select_all', false);
            })
            ->options(portaluser()->userOptions()),
    ])
Tabs\Tab::make('Reminder')
         ->schema([
             Repeater::make('reminder')
               ->label('')
                ->defaultItems(0)
                ->maxItems(3)
                ->schema([
                    Checkbox::make('customusers')
                        ->label(__('Reciver'))
                         ->live(),
                    Select::make('users')
                         ->label(__('Reciver'))
                         ->multiple()
                         ->default(function(Get $get){
                              dd($get('assigned'), $get('title')); ## returns null
                          })