Level 4
Try this:
$query->where(function ($q) use ($searchString)
{
return $q->where('product_name', 'like', '%'.searchString .'%')
->orWhere('product_Description', 'like', '%'.$searchString.'%')
->orWhere('users_user_id', 'like', '%'.$searchString.'%')
->orWhere('productNameArabic', 'like', '%'.$searchString.'%')
->orWhere('productNameEnglish', 'like', '%'.$searchString.'%')
->orWhere('productDescriptionArabic', 'like', '%'.$searchString.'%')
->orWhere('productDescriptionEnglish', 'like', '%'.$searchString.'%');
});