How to display both the elements of this category and the elements of all its subcategories when selecting a category?

Question

Django

I'm new to django, and to python too, now I'm practicing creating an online store and sent before the problem that it would be logical when choosing a category to also display products from all its subcategories. Google, unfortunately, did not help ... I think that you need to somehow filter the product correctly in the views, but how? skills are not enough to understand. Using Django-mptt for category tree (fewer db queries)

models.py

class Category(MPTTModel):
    name = models.CharField(max_length=200, db_index=True)
    slug = models.SlugField(max_length=200, db_index=True, unique=True)
    parent = TreeForeignKey('self', on_delete=models.CASCADE, null=True, blank=True, related_name='children')

    class MPTTMeta:
        order_insertion_by = ['name']

    class Meta:
        ordering = ('name',)
        verbose_name = 'Категория'
        verbose_name_plural = 'Категории'

    def get_absolute_url(self):
        return reverse('shop:product_list_by_category',
                        args=[self.slug])


    def __str__(self):
        return self.name

views.py

def product_list(request, category_slug=None):
    category = None
    categories = Category.objects.all()
    products = Product.objects.filter(available=True).order_by('-created')
    if category_slug:
        category = get_object_or_404(Category, slug=category_slug)
        products = products.filter(category=category)
    return render(request,
                  'shop/shop.html',
                  {'category': category,
                  'categories': categories,
                   'products': products})

html

<div class="category_conteiner">
    {% recursetree categories %}
        <div class="sub_menu_category">
            <a href="{{ node.get_absolute_url }}" class="subcatbtn">{{ node.name }}</a>
            {% if not node.is_leaf_node %}
            <div class="subcat_content">
                <div class="subcat_column">
                    {{ children }}
                </div>
            </div>
            {% endif %}
        </div> 
    {% endrecursetree %}

Now the sorting of products is obtained only by the category that was selected when adding the product

Answer 1

<ul class="root">
    {% recursetree nodes %}
        <li>
            {{ node.name }}
            {% if not node.is_leaf_node %}
                <ul class="children">
                    {{ children }}
                </ul>
            {% endif %}
        </li>
    {% endrecursetree %}
</ul>

doka