To get the BookMark data structure in Tree

Hi I need the nested BookMark data in the WPF C#.
I need the Title of bookMark,Src of BookMark and Unique Id.

I have To create a Object in Nested Tree means

obj1(Parent Object) is List Which contain Obj2(Child Object), Id,Text,Src

Obj2(Child Object) also contain same structure like parent object(obj1).
That is Nested
A Parent object can contain multiple child object.
A Child Object also contain multiple child object like parent.

I need the Book Mark data in this Format

I had try to crate the object from this link:
https://www.pdftron.com/pdfnet/samplecode/BookmarkTest.cs.html

Our Object Structure:

  [Serializable]
    public class NavPointElement
    {
        public string Text { get; set; }
        public string Src { get; set; }
        public List<NavPointElement> Children { get; set; }
    }

We have To set the details in This class object like NavPointList
[Serializable]
    public class TOCElement
    {
        public string DocTitle { get; set; }
        public string DocAuthor { get; set; }
        public List<Meta> MetaList { get; set; }
        public List<NavListElement> NavList { get; set; }
        public List<PageListElement> PageList { get; set; }
        public List<NavPointElement> NavPointList { get; set; }
    }

The Bookmark class exposes everything you need to recreate the TOC of a PDF.