Database
[{"_id":"123456","Continent":{"Country":[["US",{"State":[[100,{"Product":"Corn","SID":100}],[200,{"Product":"Maze","SID":200}]],}]]}}]
Query
db.collection.aggregate([{$unwind:"$Continent.Country"},{$unwind:"$Continent.Country"},{$unwind:"$Continent.Country.State"},{$unwind:"$Continent.Country.State"},{$match:{"Continent.Country.State.SID":100}},{$project:{"myProductWithSID100":"$Continent.Country.State"}}])