Get inner array value based on condition with other values in mongoose - arrays

Question

I have a DB structure as follows:
{
"Title": "AAA",
"Photos": ["/aaa/aaa.png"],
"Loc": "XXX",
"Emp": "SSS",
"Rate": [{
"Rating": 2,
"RateID": "12345654654",
"RatedDate": new Date()
}],
"Fav": [{
"FavValue": 2,
"FavID": "1111",
"FavDate": new Date()
}]
}
Here, I want to fetch all the details by default. But from array, i need to get the object that matches the ID.
In "Rate" array it needs to match "RateID" and in "Fav" array it need to match "FavID".
Both "Rate" and "Fav" wont contains objects always.
I have tried foll mongoose aggregate:
ss.aggregate([
{ $unwind: "$Rate" },
{
$group: {
"_id": '$_id',
"Title": { "$first": "$Title" },
"Loc": { "$first": "$Loc" },
"Emp": { "$first": "$Emp" },
"Photos": { "$first": "$Photos" },
"Rate": { $max: { $cond: [ { $eq: [ "$Rate.RateID", new ObjectId(id) ] }, '$Rate.Rating', null ] } },
"Fav": { $max: { $cond : [ { $eq : [{ "$size": "$Fav" }, 0]}, null, { $cond: [ { $eq: [ "$Fav.FavID", new ObjectId(id) ] }, '$Fav.FavValue', null ] } ]} }
}
}
], function (err, AvgResult) {
res.json({"result": AvgResult});
});
For "Rate", if the array is empty it returns empty result as {}
For "Fav", it returns null always if the array is empty or if it contains object
If I send the ID as '12345654654', the result should be like
{
"Title": "AAA",
"Photos": ["/aaa/aaa.png"],
"Loc": "XXX",
"Emp": "SSS",
"Rate": 2,
"Fav": null
}
If the ID is "1111", the result should be
{
"Title": "AAA",
"Photos": ["/aaa/aaa.png"],
"Loc": "XXX",
"Emp": "SSS",
"Rate": null,
"Fav": 2
}
If "Fav" is empty array in DB like "Fav": [] and ID - is "12345654654", then the result should be as follows
{
"Title": "AAA",
"Photos": ["/aaa/aaa.png"],
"Loc": "XXX",
"Emp": "SSS",
"Rate": 2,
"Fav": null
}
can any one help to get the expected result in all the above scenario..