[{"_id":"5836b91788538303","Name":"Maria","Email":"mgarciasanz@gmail.es","Age":34,"Contacts":[{"Contact_user":{"_id":"5836b916885383","Name":"Alejandro","Email":"aamericagarzon@hotmail.es","Age":32}},{"Contact_user":{"_id":"5836b916888956","Name":"Victor","Email":"ctiernocrespo@hotmail.es","Age":41}},{"Contact_user":{"_id":"5836b9168880987","Name":"Agata","Email":"adelgadosanchez@hotmail.es","Age":37}}]}]

db.collection.aggregate([{$match:{Email:"mgarciasanz@gmail.es"}},{$unwind:"$Contacts"},{$match:{"Contacts.Contact_user.Age":{$gte:36}}},{$project:{_id:0,Email:1,Contact_email:"$Contacts.Contact_user.Email",Contact_age:"$Contacts.Contact_user.Age"}}])