Question

I have nested ObsevableCollections as seen below. For simplistic reason this is sample code of what I am trying to accomplish.

Sample application the contains a ObservableCollection Team

    class MyApplication2
    {
        ObservableCollection<Team> _Teams = new ObservableCollection<Team>();
        public MyApplication2()
        {
            _Teams.Add(new Team("Team1"));
            _Teams.Add(new Team("Team2"));
            _Teams.Add(new Team("Team3"));

            foreach (Team t in _Teams)
            {
                t.Territories.Add(new Territory("Territory1"));
                t.Territories.Add(new Territory("Territory2"));
                t.Territories.Add(new Territory("Territory3"));
            }
        }
    }

Team object that contains an ObservableCollection Territory object

    class Team
    {
        private string _TeamName = "";
        private int _TeamProperty1 = 0;
        ObservableCollection<Territory> _Territories = new ObservableCollection<Territory>();

        public Team(string tName)
        {
            this.TeamName = tName;
        }

        public ObservableCollection<Territory> Territories
        {
            get { return _Territories; }
            set { _Territories = value; }
        }

        public string TeamName
        {
            get { return _TeamName; }
            set { _TeamName = value; }
        }

        public int TeamProperty1
        {
            get { return _TeamProperty1; }
            set { _TeamProperty1 = value; }
        }

    }

Territory object

    class Territory
    {
        private string _TerritoryName = "";

        public Territory(string tName)
        {
            this.TerritoryName = tName;
        }

        public string TerritoryName
        {
            get { return _TerritoryName; }
            set { _TerritoryName = value; }
        }

        public void Method1()
        {
            //Do Some Work
        }
    }

Just for this example I assigned t a value but in my real code I have the object t from some other means. t is an object type of territory in an ObservableCollection of Territories inside and object of a Team.

        public void SomeWork()
        {
            Territory t = _Teams[1].Territories[0];
            SomeMoreWork(t);
        }

I am removing a territory from 1 team and adding it to another team. Something like the following. How I get what Team object the territory belongs to?

        public void SomeMoreWork(Territory t)
        {
            Team _Team = ( Parent of t? );
            _Team.Territories.Remove(t);
            _Teams[0].Territories.Add(t);
        }

Answer 1

Thank you for the info Vincent Piel.

Thank you for the idea Saad Imran.

I changed the following and added an AssociatedTeam to my territory object and set it in the consructor. So far it seems to do what Im looking for.

    class Territory
    {
        private string _TerritoryName = "";
        Team _AssociatedTeam = null;

        public Territory(string tName, Team team)
        {
            this.TerritoryName = tName;
            this.AssociatedTeam = team;
        }

        public Team AssociatedTeam
        {
            get { return _AssociatedTeam; }
            set { _AssociatedTeam = value; }
        }

        public string TerritoryName
        {
            get { return _TerritoryName; }
            set { _TerritoryName = value; }
        }


        public void Method1()
        {
            //Do Some Work
        }
    }

And then change the initiation of territory in the constructor of MyApplication

        t.Territories.Add(new Territory("Territory1", t));
        t.Territories.Add(new Territory("Territory2", t));
        t.Territories.Add(new Territory("Territory3", t));