How can I get all nested items from a collection?

Question

I have a collection of items. The one item can have another item, and another item can have another item. So on.

I do not know how many levels of nested items can have item. The level of nested items can be defined at run-time.

class Person
{
    Person person;
    public Person(Person _nestedPerson)
    {
        person = _nestedPerson;
    }

    public bool IsSelectedPerson { get; set; }
    public string Name { get; set; }
}

and how items(Person) can be nested:

IList<Person> list = new List<Person>();            
for (int startIndex = 0; startIndex < 5; startIndex++)
{
   list.Add(new Person(new Person(new Person(new Person(null) { Name="Bill", 
        IsSelectedPerson=true})) { Name = "Jessy", IsSelectedPerson = false }) 
        { Name = "Bond", IsSelectedPerson =true});//3 nested persons
   list.Add(new Person(new Person(null) { Name = "Kendell", 
        IsSelectedPerson = true }) { Name="Rosy", IsSelectedPerson=true});//2 nested persons
   //The next time it can be just one person without nested item(person). I do not know how many items(persons) will be nested
   //list.Add(new Person(null) { Name="Rosy", IsSelectedPerson=true});
}

My goal is to take ALL objects(without duplicates) of persons(Person) who IsSelectedPerson=true?

I've played with Select()

var ee = list.Select(x=>x.IsSelectedFacet==true);//comparison should be done here

but it is not what I want, it just takes bool values.

Update:

My expected result should be have one object of Person with unique name. No matter how many there are objects with the same name. I would like to take just one object. Sorry for misleading. It should be look like this:

Answer 1

You can make a helper method to unwrap all nested objects

    IEnumerable<Person> UnwrapPerson(Person p)
    {
        List<Person> list = new List<Person>();
        list.Add(p);
        if (p.person != null)
            list.AddRange(UnwrapPerson(p.person));

        return list;
    }

Or if Person class has only one nested object (Person person;) you can use a yield construction instead of the recursion

    static IEnumerable<Person> UnwrapPerson(Person p)
    {
        yield return p;
        while (p.person != null)
        {
            p = p.person;
            yield return p;
        }
    }

In order to remove all duplicate persons, for example with the same name, you should implement IEqualityComparer<Person> and then use Distinct method.

class Comparer : IEqualityComparer<Person>
{
    public bool Equals(Person x, Person y)
    {
        return string.Equals(x.Name, y.Name);
    }

    public int GetHashCode(Person obj)
    {
        string name = obj.Name;
        int hash = 7;
        for (int i = 0; i < name.Length; i++)
        {
            hash = hash * 31 + name[i];
        }

        return hash;
    }
}

So final query should be similar to:

 list.SelectMany(p => UnwrapPerson(p))
     .Where(x => x.IsSelectedPerson == true)
     .Distinct(new Comparer())