export data in excel by view using find in set

i have three table i wanted to know how to export data using find_in_set from my database table also i wanted to know how can i export data from other tables in same excel sheet by using seconday id

here is by controller

<?php
namespace App\Http\Controllers;
use DB;
use Excel;
use App\ProductsExport;
use Illuminate\Http\Request;
class ImportExportController extends Controller
 {
   public function importExportView()
   {
     return view('dashboard.excel.export_excel');
   }
   public function export(Request $request)
   {
    return Excel::download(new ProductsExport($request->primaryCategory), 'products.xlsx');
   } 

}

and here is my model for exporting data

<?php
 namespace App;
 use App\ProductAdd;
 use Maatwebsite\Excel\Concerns\FromQuery;
 use Maatwebsite\Excel\Concerns\ShouldAutoSize;
 use Illuminate\Contracts\View\View;
 use Maatwebsite\Excel\Concerns\FromView;
 use Maatwebsite\Excel\Concerns\Exportable;
 use DB;
 class ProductsExport implements ShouldAutoSize, FromView
  {
    use Exportable;
    public $catId;
    public function __construct($catId)
    {
      $this->catId = $catId;
    }
   public function view(): View
    {
       return view('dashboard.excel.export', [
      'users' => ProductAdd::whereRaw("FIND_IN_SET(?, primaryCategory) > 0", explode(',', $this->catId))->get();
    ]);
} 

on view page ist givind blank. also please help me for importing data on three tables using same process

via Chebli Mohamed