1. Model

                   class Category(models.Model):
                    parent = models.ForeignKey('self', related_name='subCategory', 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]) 

                        

2. view

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

                 

3. template

                      {%  for i in catg %}
                            <li>{{i.title}}
                                <ul>
                                        {%  for j in i.subCategory.all %}
                                                <li>{{j.title}}

                                                        <ul>
                                                                {%  for k in j.subCategory.all %}
                                                                    <li>{{k.title}}</li>
                                                                {% endfor %}
                                                        </ul>

                                                </li>

                                        {% endfor %}

                                </ul>
                            </li>
                      
                      {% endfor %}