class objectA
{
    class objectZ
    {
        public int Count { get; set; }
    }
    class objectX
    {
        public string Prop1 { get; set; }
        public bool Prop2 { get; set; }
    }

    public string Name { get; set; }
    public objectZ Z { get; set; }
    public List<objectX> listX { get; set; }
}

BindingList<objectA> listA = new BindingList<objectA>();
comboBox_1.DataSource = listA;
comboBox_1.DisplayMember = "Name";

textBox_1.Text = listA.GetWantedObjectX().Prop1;
checkBox_1.Checked = listA.GetWantedObjectX().Prop2;

void checkBox_1_CheckedChanged()
{
    listA.GetWantedObjectX().Prop2 = checkBox_1.Checked;
}

currentObject = listA.GetWantedObjectX();
checkBox_1.Checked = currentObject.Prop2;