How to create #yield in #yield - php

Question

how to make #yield inside #yield, because the second #yield does not bring up the content that I want to release??
I'm tired of finding ways to make #yield inside #yield.
because I want to use side navigation inside side navigation, so I need a way to make #yield inside #yield.
please help
//THIS IS MY FIRST #yield (mail.blade.php)
#extends('layouts.app')
#section('content')
<div class="mail-w3agile">
<!-- page start-->
<div class="row">
<div class="col-sm-3 com-w3ls">
<section class="panel">
<div class="panel-body">
<a href="#" data-toggle="modal" data-target="#myModal1" class="btn btn-compose">
Compose Mail
</a>
<ul class="nav nav-pills nav-stacked mail-nav">
<li class="active"><a href="{{ route('mail') }}"> <i class="fa fa-inbox"></i> Inbox <span
class="label label-danger pull-right inbox-notification">9</span></a></li>
<li> <i class="fa fa-envelope-o"></i> Send Mail</li>
<li><i class="fa fa-star"></i>Favorit</li>
<li> <i class="fa fa-certificate"></i> Important</li>
<li><a href="#"> <i class="fa fa-file-text-o"></i> Drafts <span
class="label label-info pull-right inbox-notification">123</span></a></a></li>
<li> <i class="fa fa-trash-o"></i> Trash</li>
</ul>
</div>
</section>
</div>
<section id="main-content">
#yield('main-content')
</section>
</div>
<!-- page end-->
</div>
#endsection
//AND THIS IS MY SECOND #yield (inbox.blade.php)
#extends('admin.mail')
#section('main-content')
<h2>TESTING</h2>
#endsection

Answer 1

Are you looking for #stacks?
https://laravel.com/docs/6.x/blade#stacks
Instead of trying to use a mess of nested #yield you can define your side menu as a #stack('sideMenu') in the layout file, that way each time you include a blade file you would be able to add view data by targeting that specific stack with
#push('sideMenu')
This will be second...
#endpush
// Later...
#prepend('sideMenu')
This will be first...
#endprepend