Eu tenho uma matriz deste formulário:

Array
(
    [first_level] => Array
        (
            [dir_3] => Array
                (
                    [subdir_1] => Array
                        (
                            [file_2.mp4] => stdClass Object
                                (
                                    [name] => file_2.mp4
                                )

                            [file_1.mp4] => stdClass Object
                                (
                                    [name] => file_1.mp4
                                )

                        )
                )
            [dir_1] => Array
                (
                    [subdir_2] => Array
                        (
                            [file_6.mp4] => stdClass Object
                                (
                                    [name] => file_6.mp4
                                )
                            [file_9.mp4] => stdClass Object
                                (
                                    [name] => file_9.mp4
                                )
                            [file_7.mp4] => stdClass Object
                                (
                                    [name] => file_7.mp4
                                )
                        )
                    [subdir_1] => Array
                        (
                            [file_8] => stdClass Object
                                (
                                    [name] => file_8.mp4
                                )

                        )
        )
    )
)

Preciso encomendá-lo assim:

Array
(
    [first_level] => Array
        (
            [dir_1] => Array
                (
                    [subdir_1] => Array
                        (
                            [file_8] => stdClass Object
                                (
                                    [name] => file_8.mp4
                                )
                        )
                    [subdir_2] => Array
                        (
                            [file_6.mp4] => stdClass Object
                                (
                                    [name] => file_6.mp4
                                )
                            [file_7.mp4] => stdClass Object
                                (
                                    [name] => file_7.mp4
                                )
                            [file_9.mp4] => stdClass Object
                                (
                                    [name] => file_9.mp4
                                )
                        )
        )
        [dir_3] => Array
                (
                    [subdir_1] => Array
                        (
                            [file_1.mp4] => stdClass Object
                                (
                                    [name] => file_1.mp4
                                )

                            [file_2.mp4] => stdClass Object
                                (
                                    [name] => file_2.mp4
                                )

                        )
                )
    )
)

Naveguei por outras perguntas semelhantes e tentei resolvê-lo comusort mas eu não conseguia entender. : S

Qualquer ideia?