Problem with django formsets

I have a few Django models as such:
FirstModel: (has only name and few other fields)

class FirstModel(models.Model):
    name = models.CharField(max_length=100)

SecondModel: (has services that will relate to FirstModel, this doesn’t have any fks)

class SecondModel(models.Model):
    name = models.CharField(max_length=100)
    service = models.booleanField(default=False)

ThirdModel: (Relates First and Second Models with FKs to both models)

class ThirdModel(models.Model):
    first_model = models.ForeignKey(FirstModel, on_delete=models.CASCADE)
    second_model = models.ForeignKey(SecondModel, on_delete=models.CASCADE)

I have a view to update the FirstModel, which lists the fields in the First Model, and also include the formset for listing Third model objects related to first model. This is working fine till here.

class UpdateFirstModelView(UpdateView):
    form_class = FirstModelForm
    template_name = "templates/first_model/manage.html"
    context_object_name = "first_provider"

    def get_context_data(self, **kwargs):
         context = super(UpdateFirstModelView, self).get_context_data(**kwargs)
         context["first_provider_form"] = context["form"}
         context["third_model_formset"] = ThirdModelFormset(queryset=ThirdModel.objects.filter(first_model=self.get_object()), first_model=self.get_object(),)
         return context 

The formset for third model looks something like this:

class BaseThirdModelFormset(BaseModelFormSet):
    def __init__(self, *args, **kwargs):
        queryset = kwargs.pop("queryset", ThirdModel.objects.none())
        first_model = kwargs.pop("first_model", None)
        super().__init__(*args, **kwargs)

        self.queryset = queryset
        self.extra = 1
        for form in self.forms:
            if not form.initial:
                # Set the initial value for the parent provider field
                form.initial["first_model"] = first_model
                form.fields["second_model"] = ModelChoiceFieldShowName( # This is a custom function
                    empty_label="Add a Second Model Type,
                    widget=forms.Select(attrs={"class": "form-control"}),

ThirdModelFormset = modelformset_factory(
    fields=["first_model", "second_model"],
    widgets={"first_model": forms.HiddenInput()},

Now I want to add a new one to one model for third model, FourthModel. This model will have a few fields.

class FourthModel(models.Model):
    name = models.OneToOneModel(ThirdModel, on_delete=models.CASCADE)

I want to show a button in the template to set the values of Fourth Model where I show the Third Model. But I can’t seem to send a formset for the FourthModel within the ThirdModelFormset.
I want FirstForm>ThirdForm>FourthForm within the context. Is this possible directly?

There’s no need for a formset here. A formset is a wrapper around a list of forms. However, with a one-to-one relationship, you’re only ever going to have one form. All that’s needed is to create a form for FourthModel with the name field set to the related ThirdModel.

Side note: I hope you realize that what you’ve actually created is a many-to-many relationship between FirstModel and SecondModel where ThirdModel is the through table. Changing your model definitions to reflect that could make some of your other operations easier by allowing for the use of the many-to-many relationship manager.