MongoDB query array elements

I'm new to Mongodb,trying to fetch array values from nested array,i need to get all the values of array "1" from the below example(open,isnot,closed,any) ,without passing any value of array , something like

var cursor = db.collection('details').find({ "tracker.1" });

"_id" : ObjectId("5934f65bdab27e02aa954891"),"tracker" : [ 
    {

        "1" : [ 
            "open", 
            "isnot", 
            "closed", 
            "any"
        ],
        "2" : [ 
            "task", 
            "user story", 
            "bug", 
            "support", 
            "feature", 
            "ui modification", 
            "enhancment", 
            "use case"
        ]
    }
],
"subject" : [ 
    {
        "1" : [ 
            "contains", 
            "doesnot contain", 
            "none", 
            "any"
        ]
    }
]}

via Prem Sanil