db={"orders":[{"_id":"625335297fcc20782bcdf085","title":"Evento 1","description":"lorem ipsum evento 1","img":"nao implementado","value":0,"remainingVacancies":14,"isSingleDay":false,"dateByDay":[{"initialDate":"2022-04-10T21:17:09.785Z","finalDate":"2022-04-10T21:17:09.785Z","_id":"62534955171ecadae7ff6cd4"},{"initialDate":"2022-04-10T21:17:09.785Z","finalDate":"2022-04-10T21:17:09.786Z","_id":"62534955171ecadae7ff6cd5"}],"__v":0}],"presentations":[{"_id":"62549d4d3b41827fe7593332","title":"Apresentação 1","description":"lorem ipsum 11 testee","img":"nao implementado","value":0,"remainingVacancies":14,"isSingleDay":true,"dateByDay":[{"initialDate":"2022-04-11T21:27:41.823Z","finalDate":"2022-04-11T21:27:41.823Z","_id":"62549d4d3b41827fe7593333"}],"eventId":"625335297fcc20782bcdf085","__v":0}]}

db.orders.aggregate([{$match:{_id:"625335297fcc20782bcdf085"}},{$lookup:{from:"presentations",localField:"_id",foreignField:"eventId",as:"registeredPresentations"}},{$unwind:"$registeredPresentations"},{$project:{_id:0,registeredPresentations:1}},{$replaceWith:"$registeredPresentations"}])