MongoDB finding all subdocuments where subDocument _ids like "string" -

sample document structure like:

{     "_id" : "https://docs.mongodb.org/manual",     "collection" : {         "_id" : "collection",         "urls" : [              "https://docs.mongodb.org/manual/c1",              "https://docs.mongodb.org/manual/c2"         ]     },     "collectionnew" : {         "_id" : "collection1",         "urls" : [              "https://docs.mongodb.org/manual/c1new",              "https://docs.mongodb.org/manual/c2new"         ]     },     "log" : {         "_id" : "log",         "urls" : [              "https://docs.mongodb.org/manual/l1",              "https://docs.mongodb.org/manual/l2"         ]     } } 

i have multiple such documents in collection. after finding document

db.autosearch.find({"_id": "https://docs.mongodb.org/manual"}) 

i want search subdocuments under name "collection"

solution

i changed document structure to:

{ "_id" : "https://docs.mongodb.org/manual", "contents" : [      {         "_id" : "connect",         "urls" : [              "https://docs.mongodb.org/manual/search/?query=connect"         ]     },      {         "_id" : "connection",         "urls" : [              "https://docs.mongodb.org/manual/search/?query=connection",              "https://docs.mongodb.org/manual/search/?query=connection%20pymongo"         ]     }     {         "_id" : "list",         "urls" : [              "https://docs.mongodb.org/manual/search/?query=listfiles",              "https://docs.mongodb.org/manual/search/?query=listdatabases",              "https://docs.mongodb.org/manual/search/?query=listcommands"         ]     },      {         "_id" : "log",         "urls" : [              "http://docs.mongodb.org/manual/tutorial/rotate-log-files/",              "http://docs.mongodb.org/manual/reference/log-messages/"         ]     },      {         "_id" : "index",         "urls" : [              "https://docs.mongodb.org/manual/search/?query=index-related%20commands"         ]     } ]} 

then using mongodb aggregate query

db.autosearch.aggregate([{$match:{ "_id": "https://docs.mongodb.org/manual"}},                      {$unwind: '$contents'},                     {$match:{"contents._id":/connect/}}]) 

i got desired output.