Database
[{"_id":ObjectId("62021f4cbd7796d438622245"),"id":"MyData","Mode":"txtx","MinCost":"0.2","R:1":"info1","R:13":"info2","R:3":"info3","R:4":"info4","R:5":"info5","Cost":"100"}]
Query
db.collection.aggregate([{"$match":{$expr:{"$gte":[{$size:{"$filter":{"input":{"$objectToArray":"$$ROOT"},"as":"s","cond":{"$regexFind":{"input":"$$s.k","regex":"R:1"}}}}},1]}}},{"$replaceRoot":{"newRoot":{"$arrayToObject":{"$filter":{"input":{"$objectToArray":"$$ROOT"},"as":"s","cond":{"$regexFind":{"input":"$$s.k","regex":"R:1"}}}}}}}])