fetch parent data and child data use laravel

I am using laravel 5.7. I want to show child data using by Parent id

I make CategoryController . i fetch all data by parent id show here . But i want to show all data index page.

    $parentCat = Category::where('parent',0)->get();
    foreach($parentCat as $parent){
        echo "<pre>";
        echo $parent->category_name;
         $category  = Category::where('parent',$parent->id)->get();

         foreach ($category as $child){
              echo "<pre>";
             echo $child->category_name;
         }

    }
   return view('fnf.category.index')->with('parent',$parentCat);

Controller show

<table class="table table-striped">
        <tr>
            <th>Man</th>
              <th><a href=""> Edit</a></th>
        </tr>
        <tr>
            <td>Shirt</td>
            <td><a href=""> Edit</a></td>
        </tr>
        <tr>
            <td>Shirt</td>
            <td><a href=""> Edit</a></td>
        </tr>
        <tr>
            <th>Woman</th>
            <th><a href=""> Edit</a></th>
        </tr>
        <tr>
            <td>Woman Shirt</td>
            <td><a href=""> Edit</a></td>
        </tr>
    </table>

via Chebli Mohamed