Filter the collection but sort by internal property

Considering that I have a collection of documents like the following, and I would like to get the information returned like this:

Select all items in a campaign campaignID = 12, entries.questionscorrectin descending order (capped at 10).

I've done jabs on a lot of queries, but I seem to be stuck with the fact that I'm selecting on one level, but want to order on a lower level (i.e. attributes).

Here is what I have so far:

db.getCollection('main').find({"id":4}, {"entries": 1}).sort({"questionscorrect": -1}).limit(2)

How can I write this code in Go (Mgo) syntax or direct MongoDB query?

I keep getting the information returned but sorted by quantity

{
    "_id": ObjectId("57f4a590a4be269aa54a0505"),
    "campaignID": 12,
    "name": "name-here",
    "description": "description-here",
    "entries": [{
        "id": 1,
        "nickname": "conorh",
        "name": "conor h***",
        "email": "[email protected]",
        "agreeTerms": true,
        "optInMarketing": false,
        "questionscnswered": 10,
        "questionscorrect": 3
    }, {
        "id": 2,
        "nickname": "bobs",
        "name": "bob smyth",
        "email": "[email protected]",
        "agreeTerms": true,
        "optInMarketing": false,
        "questionscnswered": 10,
        "questionscorrect": 6
    }, {
        "id": 3,
        "nickname": "jd12",
        "name": "jane doe",
        "email": "[email protected]",
        "agreeTerms": true,
        "optInMarketing": false,
        "questionscnswered": 10,
        "questionscorrect": 1
    }]
}