Database
[{"_id":{"userArea":NumberInt(4927)},"pages":{"12":{"page":NumberInt(2635),"progress":"COMPLETED","progressType":"USER_PROGRESS","end":11},"13":{"page":NumberInt(2627),"progress":"COMPLETED","progressType":"USER_PROGRESS","end":"2018-04-19T15:04:29.000+0000"},"14":{"page":NumberInt(2627),"progress":"CANCELLED","progressType":"USER_PROGRESS","end":"2018-04-19T15:04:29.000+0000"}}}]
Query
db.collection.aggregate([{"$project":{"pages":{"$arrayToObject":{"$filter":{"input":{"$objectToArray":"$pages"},"cond":{"$ne":["$$this.v.progress","CANCELLED"]}}}}}}])