object nested into a nested array, how to implement a custom filter for it?

I have an application that I am constructing with a friend and we have a very big problem: I have a very big json with some nested arrays an objects, I am using a filter with an ng-model="search" the filter (search) works great with the top level array which is named sports, but once I try to search through the leagues array, the filter returns nothing. I saw in another question that I can search(filter) based on nested properties which is exactly what I want. I tried to follow the example answer on that question but I am having a problem trying to solve this. Someone else says: that is not possible with this kind of matching that you are trying because you want to filter through a matching sport.name and all of his matching and not non matching leagues or a non matching sport.name and only his matching leagues.

json

     [
      {
        "name": "Cricket",
        "leagues": []
      },
      {
        "name": "NBA Games",
        "leagues": [
          {
            "name": "NBA",
            "sport": {
              "id": 8,
              "name": "NBA Earliest"
            },
            "lineType": "G",
            "priority": [
              1,
              3
            ],
            "part": "0"
          }
        ]
      },
      {
        "name": "COLLEGE Basketball",
        "leagues": [
          {
            "name": "College - NCAA BASKETBALL",
            "sport": {
              "id": 24,
              "name": "College Basketball"
            },
            "lineType": "G",
            "priority": [
              0,
              4
            ],
            "part": "0"
          },
          {
            "name": "NCAA BASKETBALL ADDED GAMES",
            "sport": {
              "id": 24,
              "name": "College Basketball"
            },
            "lineType": "G",
            "priority": [
              1,
              4
            ],
            "part": "0"
          },
          ...

my html

<input type="search" ng-model="search">

<div ng-repeat="sport in sports | filter: query">

     <!-- searching (filtering) great --> 
     <div>{{sport.name}}</div>
   </div>

   <div ng-repeat="league in sport.leagues | filter: query">

      <!-- here is not filtering at all -->
        {{league.name}}
   </div>
</div>

can I do it this way I am trying or how do I implement a custom filter for this ?