How to filter data and show it in master details view

My Data

var myData= {
  user:[{id:"1",firstname:"x",lastname:"k"},
  {id:"2",firstname:"y",lastname:"k"},
  {id:"3",firstname:"z",lastname:"k"}],
  expense:[{expenseno:"1",uid:"1",item:"c",amount:"1500"},
  {expenseno:"2",uid:"2",item:"t",amount:"1150"},
  {expenseno:"3",uid:"3",item:"p",amount:"500"},
  {expenseno:"4",uid:"1",item:"y",amount:"1000"},
  {expenseno:"5",uid:"2",item:"t",amount:"3500"},
  {expenseno:"6",uid:"3",item:"s",amount:"3500"},
  {expenseno:"7",uid:"1",item:"q",amount:"900"}],

};

I want to create a SplitApp(Master-Details page). I have created the Master page as a List of User Name from the User dataset. The list should contain the firstname.

var oList = new sap.m.List({
  id:"listId",
  mode: sap.m.ListMode.SingleSelect,
  select: function(){
  oController.itemSelected();
  }
  });
  var oItemTemplate = new sap.m.StandardListItem({
  id: "sList",title:"{firstname}"});
  oList.bindAggregation("items","/user",oItemTemplate );
  return new sap.m.Page({
  id:"master",
  title: "Claims",
  content: [oList]
  });  

Now in details page I want to show the expenses made by that user(when i select a specific user from master view) in a table.

Now my question is how to filter data and use it for the Details view. Example: If I select User "X" from Master view list, I should get id 1 from the "user" and Expenseno 1,4 and 7 (as they are associated with uid 1) from "expense", finally i will show the expenses of uid 1 in the details view.

Code I am trying

itemSelected: function(){
var app = sap.ui.getCore().byId("appId");
var list = sap.ui.getCore().byId("listId");//will get instance of the list
var sItem = list.getSelectedItem();//should know which item we selected

//*** How To filter ***//

//var Model = new sap.ui.model.json.JSONModel(oitem); // will use it for details
//sap.ui.getCore().setModel(Model,'item');// view(oitem should contain the filtered data)

app.toDetail("detailsid","show");
},