Tabs to filter the records(Panel Builder) not working

use Filament\Resources\Components\Tab;
use Illuminate\Database\Eloquent\Builder;

public function getTabs(): array
    {
        return [
            'all' => Tab::make('All Applicants')
                ->badge(CourseApplication::query()->count())
                ->icon('heroicon-m-user-group'),
            'part' => Tab::make('Part Payment')
                ->icon('heroicon-m-beaker')
                 ->badge(CourseApplication::query()->whereRaw("cost > 0 And cost > paid")->count())
                ->modifyQueryUsing(fn(Builder $query) => $query->whereRaw("cost > 0 And cost > paid")),
            'full' => Tab::make('Full Payment')
               ->badge(CourseApplication::query()->whereRaw("cost = paid")->count())
                ->modifyQueryUsing(fn(Builder $query) => $query->whereRaw("cost = paid"))
                ->icon('heroicon-m-banknotes'),
        ];
    }