db={"phone":[{"_id":ObjectId("63d8d39206c9f93e68d27206"),"brand":"Apple","model":"iPhone XR","year":2016,"image":"https://apple-mania.com.ua/media/catalog/product/cache/e026f651b05122a6916299262b60c47d/a/p/apple-iphone-xr-yellow_1.png","CPU":{"manufacturer":"A12 Bionic","cores":10},"misc":["Bluetooth 5.0","NFC","GPS"],"factory_id":ObjectId("63d8d42b7a4d7a7e825ef956")}],"factory":[{"_id":ObjectId("63d8d42b7a4d7a7e825ef956"),"name":"Foxconn","stock":1000}]}

db.phone.aggregate([{"$match":{"brand":"Apple"}},{"$lookup":{"from":"factory","localField":"factory_id","foreignField":"_id","as":"factories"}},{"$project":{"model":1,"image":1,"factory":{"$arrayElemAt":["$factories",0]}}}])