[Answered ]-Django Rest Framework nested serializer

You can create a SectorSerializer which will contain a nested serializer InsectorSerializer.

Since you are using different keys for output we can use source to get the corresponding values from the field names.

name key in the output corresponds to sector_mc, so we use sector_mc as its source.

children key in the output contains all the related instances for a particular Sectors instance. We can use FOO_set as the source for children field. Also, since there will be multiple related instances, we pass many=True parameter along with it.

class InsectorSerializer(serializers.ModelSerializer):

    class Meta:
        model = Insector
        fields = ('name', 'value')


class SectorSerializer(serializers.ModelSerializer):
    name = serializers.CharField(source='sector_mc') # get value from 'sector_mc' 
    children = InsectorSerializer(many=True, source='insector_set') # get all related instances

    class Meta:
        model = Sectors
        fields = ('name', 'children')