How To Make A Sub And Sub Sub Categories In Django [Most Important]

Github Repo:- https://github.com/ShivamRohilllaa/django-
categories-tree

class Category(models.Model):
    parent = models.ForeignKey('self', related_name='children', on_delete=models.CASCADE, blank = 
    True, null=True)
    title = models.CharField(max_length=100) 
    slug = AutoSlugField(populate_from='title', unique=True, null=False, editable=False)
    created_at = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return self.title

    class Meta:
        #enforcing that there can not be two categories under a parent with same slug

        # __str__ method elaborated later in post.  use __unicode__ in place of

        unique_together = ('slug', 'parent',)    
        verbose_name_plural = "categories"     

    def __str__(self):                           
        full_path = [self.title]                  
        k = self.parent
        while k is not None:
            full_path.append(k.title)
            k = k.parent
        return ' -> '.join(full_path[::-1])

def home(request):
    catg = Category.objects.filter(parent=None)
    context = {'catg':catg}    
    return render(request, 'index.html', context)