Remote.java

 public void RemoteClass(){
 
 //funcion con el service de getAllGeneros
 private Observable<GenerosResponse> makeRequestToServiceGender() { 
        return  service.getAllGeneros("movie","list","key"); //some network call
    }

 //funcion con el service de getAllMovies
    private Observable<ResponseMovies> makeRequestToServiceMovies(Genre genre) {
        return service.getAllMovies(genre.getId(),"movies","key","created_at.asc"); //some network call based on response from ServiceA
    }

    void doTheJob() {

        makeRequestToServiceGender()
        .flatMap(userResponse -> Observable.just(userResponse.getGenres()))      //get list from response
                .flatMapIterable(baseDatas -> baseDatas) //realizamos una interaccion por genero
                .flatMap(new Func1<Genre, Observable<? extends ResponseMovies>>() {

                    @Override
                    public Observable<? extends ResponseMovies> call(Genre genre) {
                        return makeRequestToServiceMovies(genre);//consumimos el servicio peliculas con el objeto genero
                    }
                }, new Func2<Genre, ResponseMovies, CollectionsMovies>() {

                    @Override
                    public CollectionsMovies call(Genre genre, ResponseMovies responseMovies) {
                        return new CollectionsMovies(genre,responseMovies);//Obtenemos ambas respuestas y creamos el objeto  "CollectionsMovies"
                    }
                }).
                subscribeOn(Schedulers.newThread())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Subscriber<CollectionsMovies>() {
                    @Override
                    public void onCompleted() {
                    
                    }

                    @Override
                    public void onError(Throwable e) {

                    }

                    @Override
                    public void onNext(CollectionsMovies collectionsMovies) {
                      //Objeto el cual contiene el objeto genero y el objeto peliculas ;) 
                    }
                });
 }