Create objects in multiple nested serializer in django

I have 3 models which are related to each other via ManytoMany relation like this:

class DemandEvents(models.Model):

    date = models.DateTimeField(blank=True, null=True)
    quantity = models.IntegerField(default=0)

class DemandFlows(models.Model):

    events = models.ManyToManyField(DemandEvents)
    flow = models.ForeignKey(Flow, on_delete=models.CASCADE)
    kit = models.ForeignKey(Kit, on_delete=models.CASCADE)
    monthly_quantity = models.IntegerField(default=0)

class Demand(models.Model):

    demand_flows = models.ManyToManyField(DemandFlows)
    delivery_month = models.DateTimeField(blank=True, null=True)
    owner = models.ForeignKey(User, on_delete=models.CASCADE)

I am trying to create the serializers for this but keep getting confused how to handle the multi-level nesting

Serializer.py

class DemandEventsSerializer(serializers.ModelSerializer):

    class Meta:
        model = DemandEvents
        fields = "__all__"

class DemandFlowsSerializer(serializers.ModelSerializer):

    class Meta:
        model = DemandFlows
        fields = "__all__"

class DemandSerializer(serializers.ModelSerializer):

    demand_flows = DemandFlowsSerializer(many=True)

    class Meta:
        model = Demand
        fields = "__all__"


    def create(self, validated_data):
        items_objects = validated_data.pop('form_list', None)
        prdcts = []
        for item in items_objects:
            i = DemandFlows.objects.create(**item)
            prdcts.append(i)
        instance = Demand.objects.create(**validated_data)
        instance.demand_flows.set(prdcts)
        return instance

How do I add events data to this DemandFlows?