Updating a double nested array MongoDB

Consider this schema:

let userSchema = new mongoose.Schema({
id: String,
displayName: String,
displayImage: String,
posts: [
    {
        url: String,
        description: String,
        likes: [String],
        comments: [
            { content: String, date: String, author: { id: String, displayName: String, displayImage: String } }
        ]
    }
]
});

I am able to delete a certain item from the comments array using this query

controller.deleteComment = (req, res, next) => {
User.findOneAndUpdate(
    { id: req.query.userid, 'posts._id': req.params.postid, },
    {
        $pull: {
            'posts.$.comments': { _id: req.body.commentID },
        }
    }
)
    .exec()
    .then(() => {
        res.send('deleted');
    })
    .catch(next);
};

Is there anyway that I can UPDATE an element inside the comments array by using the $set operator? I need to changed the contents of a comment based on its comment ID.. something like this:

controller.editComment = (req, res, next) => {
    User.findOneAndUpdate(
        { id: req.query.userid, 'posts._id': req.params.postid, 'comments._id':req.body.commentID },
        {
            $set: {
                'posts.$.comments': {  content: req.body.edited },
            }
        }
    )
        .exec()
        .then(() => {
            res.send('deleted');
        })
        .catch(next);
};

This ^ is obviously not working but I'm wondering if there is a way I can do this?

via JohnSnow