How does mongdb manipulate subdocument arrays (query and return subarrays, add or modify specified index entries)?

Collection a has the following documents:

{
    "_id" : ObjectId("5acd77c763c9b117b48b2e92"),
    "Symbol" : "item01",
    "min5" : [ 
        {
            "Symbol" : "item01",
            "Date" : "2017-01-31",
            "price" : 5000
        }, 
        {
            "Symbol" : "item01",
            "Date" : "2017-01-30",
            "price" : 4999
        }, 
         {
            "Symbol" : "item01",
            "Date" : "2017-01-29",
            "price" : 4998
        }
        ...
    ],
    "min10" : [ 
        {
            "Symbol" : "item01",
            "Date" : "2017-01-31",
            "price" : 5010
        }, 
        {
            "Symbol" : "item01",
            "Date" : "2017-01-30",
            "price" : 5009
        }, 
         {
            "Symbol" : "item01",
            "Date" : "2017-01-29",
            "price" : 5008
        }
        ...
    ]
}
{
    "_id" : ObjectId("5acd77c763c9b117b48b2e91"),
    "Symbol" : "item02",
    "min5" : [ 
        {
            "Symbol" : "item02",
            "Date" : "2017-01-31",
            "price" : 2000
        }, 
        {
            "Symbol" : "item02",
            "Date" : "2017-01-30",
            "price" : 1999
        }, 
         {
            "Symbol" : "item02",
            "Date" : "2017-01-29",
            "price" : 1998
        }
        ...
    ],
    "min10" : [ 
        {
            "Symbol" : "item02",
            "Date" : "2017-01-31",
            "price" : 2010
        }, 
        {
            "Symbol" : "item02",
            "Date" : "2017-01-30",
            "price" : 2009
        }, 
         {
            "Symbol" : "item02",
            "Date" : "2017-01-29",
            "price" : 2008
        }
        ...
    ]
}
{
    "_id" : ObjectId("5acd77c763c9b117b48b2e90"),
    "Symbol" : "item03",
    "min5" : [ 
        {
            "Symbol" : "item03",
            "Date" : "2017-01-31",
            "price" : 3000
        }, 
        {
            "Symbol" : "item03",
            "Date" : "2017-01-30",
            "price" : 2999
        }, 
         {
            "Symbol" : "item03",
            "Date" : "2017-01-29",
            "price" : 2998
        }
        ...
    ],
    "min10" : [ 
        {
            "Symbol" : "item03",
            "Date" : "2017-01-31",
            "price" : 3010
        }, 
        {
            "Symbol" : "item03",
            "Date" : "2017-01-30",
            "price" : 3009
        }, 
         {
            "Symbol" : "item03",
            "Date" : "2017-01-29",
            "price" : 3008
        }
        ...
    ]
}

given the following conditions:
item02 , min5 , return 2 , how to query and return content in the following format:

[{"Symbol":"item02","Date":"2017-01-31","price":2000},{"Symbol":"item02","Date":"2017-01-30","price":1999}]

there is also how to add, delete, modify and check the item members of the array"s index operation subdocuments array.

I am using the mongodb package in Node.js.

I still don"t understand after looking up it on the Internet and in the document for a long time. Thank you for your advice. Thank you!