Buscar en una matriz de MongoDB
> db.demo396.aggregate([
... { "$lookup": {
... "from": "demo395",
... "let": { "details": "$details" },
... "pipeline": [
... { "$match": { "$expr": { "$in": [ "$_id", "$$details" ] } } }
... ],
... "as": "output"
... }}
... ])
Condemned Cottonmouth