Database
db={"computer":[{"_id":ObjectId("6319bd1540b41d1a35717a16"),"name":"MyComputer","configs":{"ybe":{"refId":ObjectId("61e56339b528bf009feca149"),"name":"Ybe Config"},"test":{"refId":ObjectId("61f3d7ec47805d1443f14540"),"name":"TestConfig"},}}],"coll":[{_id:ObjectId("61e56339b528bf009feca149")}]}
Query
db.coll.aggregate([{"$lookup":{"from":"computer","let":{id:"$_id"},"pipeline":[{$set:{configs:{"$objectToArray":"$configs"}}},{"$unwind":"$configs"},{$match:{$expr:{$eq:["$$id","$configs.v.refId"]}}}],"as":"computers"}}])