Filtering nested objects in angular dynamically?

Question

I have a data set that I have retrieved from a service and have used ng-repeat to display. I need to filter this data based on a number of select elements which have been set up with ng-model=<a_name>.

Here is the repeated element:

 <li ng-repeat="item in dota_have_items | orderItemsBy:'pos':false | filter:search | itemFilter:rarity:'rarityProperName'">

In the above, search and rarity are such ng-models.

Here is an example of the json data:

[
    {
        "user": "u2122", 
        "item": {
            "defindex": 15059, 
            "name": "Bloodstone of the Precursor", 
            "itemClass": "Socket Gem", 
            "imageUrl": "http://cdn.dota2.com/apps/570/icons/econ/tools/bloodstone2.f4936e5a87dc66b47dbe653101cfc17de34176e6.png", 
            "itemHero": null, 
            "itemRarity": {
                "rarityProperName": "Mythical", 
                "rarityColor": "#8847ff"
            }
        }, 
        "item_classid": "170676805", 
        "untradable": true, 
        "item_quality": {
            "dotaName": "Standard", 
            "qualityColor": "#D2D2D2"
        }, 
        "custom_name": null, 
        "custom_desc": null, 
        "uses": 1, 
        "in_trade": false, 
        "pos": 2
    }
] 

NOTE: Yes i understand my naming conventions are terrible. I plan on fixing this as soon as I get this working.

Now I have created a custom filter('itemFilter'):

Search.filter('itemFilter', function(){
    return function(items, model, field) {
        if(angular.isUndefined(model)==true || model==null || model==''){
            return items;
        }
        console.log((model.charAt(0).toUpperCase() + model.slice(1)));
        var filtered = [];
        angular.forEach(items, function(item){
            console.log(item.field);
            if(item[field] == (model.charAt(0).toUpperCase() + model.slice(1)) ){
                filtered.push(item);
            }
        });
        return filtered;
    }
});

Here's the problem. I want to make this filter so that I pass it the items, ng-model, and field that I want the model mapped to. For example, ng-model=rarity I passed 'itemRarity'. Now what I want to do is find the field, check if the model value is the same and if so add it to the filtered array. Seems so simple but I am not sure how to iterate through the nested object to find the field.

Is there a way to directly find a key within a json object?

SOLUTION: Taken from another post

Wasnt 100% what I was looking for since I didnt want to specify the entire path to the property but it does the job well.