MongoDB query embedded document array

I have the following document:

{
    "_id" : ObjectId("59299670266cc82a042f3817"),
    "_userId" : ObjectId("590a08dba07c1a1bee87b310"),
    "name" : "My home",
    "floors" : [ 
        {
            "_id" : ObjectId("59299670266cc82a042f4541"),
            "name" : "Floor 1",
            "rooms" : [ 
                {
                    "_id" : ObjectId("59299670266cc82a042f4551"),
                    "name" : "Room 1",
                    "devices" : [
                        {
                            "_id" : ObjectId("59299670266cc82a042f4561"),
                            "name" : "Device 1"
                        },
                        {
                            "_id" : ObjectId("59299670266cc82a042f4562"),
                            "name" : "Device 2"
                        }
                    ]
                },
                {
                    "_id" : ObjectId("59299670266cc82a042f4552"),
                    "name" : "Room 2",
                    "devices" : [
                        {
                            "_id" : ObjectId("59299670266cc82a042f4563"),
                            "name" : "Device 3"
                        },
                        {
                            "_id" : ObjectId("59299670266cc82a042f4564"),
                            "name" : "Device 4"
                        }
                    ]
                }
            ]
        },
        {
            "_id" : ObjectId("59299670266cc82a042f4542"),
            "name" : "Floor 2",
            "rooms" : [ 
                {
                    "_id" : ObjectId("59299670266cc82a042f4553"),
                    "name" : "Room 1",
                    "devices" : [
                        {
                            "_id" : ObjectId("59299670266cc82a042f4565"),
                            "name" : "Device 5"
                        },
                        {
                            "_id" : ObjectId("59299670266cc82a042f4566"),
                            "name" : "Device 6"
                        }
                    ]
                },
                {
                    "_id" : ObjectId("59299670266cc82a042f4554"),
                    "name" : "Room 2",
                    "devices" : [
                        {
                            "_id" : ObjectId("59299670266cc82a042f4567"),
                            "name" : "Device 7"
                        },
                        {
                            "_id" : ObjectId("59299670266cc82a042f4568"),
                            "name" : "Device 8"
                        }
                    ]
                }
            ]
        }
    ]
}

And I would like to get a list of all devices:

[
    {
        "_id" : ObjectId("59299670266cc82a042f4561"),
        "name" : "Device 1"
    },
    {
        "_id" : ObjectId("59299670266cc82a042f4562"),
        "name" : "Device 2"
    },
    {
        "_id" : ObjectId("59299670266cc82a042f4563"),
        "name" : "Device 3"
    },
    {
        "_id" : ObjectId("59299670266cc82a042f4564"),
        "name" : "Device 4"
    },
    {
        "_id" : ObjectId("59299670266cc82a042f4565"),
        "name" : "Device 5"
    },
    {
        "_id" : ObjectId("59299670266cc82a042f4566"),
        "name" : "Device 6"
    },
    {
        "_id" : ObjectId("59299670266cc82a042f4567"),
        "name" : "Device 7"
    },
    {
        "_id" : ObjectId("59299670266cc82a042f4568"),
        "name" : "Device 8"
    }
]

Is that possible with MongoDB?

I've tried it with aggregate and { $unwind: $floors.rooms.devices } or

{ $unwind: $floors }
{ $unwind: $floors.rooms }
{ $unwind: $floors.rooms.devices }

but the output is always empty. I don't know if I would get the output I want with $unwind at all.

Because I'm also using aggregate for other things a solution with it would be nice.

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