[{"_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"}}}]

db.collection.aggregate([{"$set":{"pages":{"$objectToArray":"$pages"}}},{"$project":{"pages":{"$arrayToObject":{"$filter":{"input":"$pages","cond":{"$ne":["$$this.v.progress","CANCELLED"]}}}}}},{"$replaceRoot":{"newRoot":"$pages"}}])