[{"_id":"693ae6dc320b2bb92635361e","cards":[{"_id":"600056266","users":[{"_id":"EafXiJktdKSM45OcnniU4gpcGWc2","vote":{"234":{"W":"56","M":"543","R":"322"},"235":{"W":"554","M":"332","R":"454"}}},{"_id":"EafXiJktdKSM45OcnniU4gpcGWPR4","vote":{"234":{"W":"54","M":"69","R":"987"},"235":{"W":"85","M":"751","R":"65"}}}]}]},{"_id":"693ae6dc320b2bb92633ew23","cards":[{"_id":"600056266","users":[{"_id":"EafXiJktdKSM45OcnniU4gpcGWc2","vote":{"234":{"W":"56","M":"543","R":"322"},"235":{"W":"554","M":"332","R":"454"}}},{"_id":"EafXiJktdKSM45OcnniU4gpcGWPR4","vote":{"234":{"W":"54","M":"69","R":"987"},"235":{"W":"85","M":"751","R":"65"}}}]}]}]

db.collection.aggregate([{$match:{_id:"693ae6dc320b2bb92635361e"}},{$project:{cards:{$filter:{input:"$cards",as:"card",cond:{$eq:["$$card._id","600056266"]}}}}},{$unwind:"$cards"},{$project:{users:{$filter:{input:"$cards.users",as:"user",cond:{$eq:["$$user._id","EafXiJktdKSM45OcnniU4gpcGWc2"]}}}}},{$unwind:"$users"},{"$replaceWith":"$users.vote"}])