[Answered ]-Django Rest Framework get filtered queryset in custom get function

Try to use self.queryset in filter_queryset() method inside get() method so:

from rest_framework.views import APIView

class MyAPIView(APIView):
    queryset = MyObject.objects.all()
    filter_backends = [MyCustomFilterBackend, DjangoFilterBackend]
    filterset_fields = ["field1", "field2"]

    def filter_queryset(self, queryset):
        for backend in list(self.filter_backends):
            queryset = backend().filter_queryset(self.request, queryset, self)
        return queryset

    def get(self, request):
        queryset = self.filter_queryset(self.queryset)
        s = StatManager(queryset)
        return Response(s.dashboard())