Database

[{"_id":123,"chat_id":125},{"_id":234,"chat_id":1325},{"_id":1323,"chat_id":335},]

Query

db.collection.aggregate([{"$match":{"_id":123}},{"$addFields":{"chat_id":-10013345566,}},{"$merge":{"into":"collection","on":"_id","whenMatched":"merge"}},])

Result