Database
[{field1:"one",field2:"two",field3:"three",rm:["field1","field2"]}]
Query
db.collection.aggregate([{"$set":{"kv":{"$filter":{"input":{"$objectToArray":"$$ROOT"},"as":"field","cond":{"$not":{"$in":["$$field.k","$rm"]}}}}}},{"$replaceRoot":{"newRoot":{"$arrayToObject":"$kv"}}},{"$merge":{"into":"collection","on":"_id"}}])