VirtualDBTree - how to use that component?

Question

I want display some tree-data with unlimited depth:

Root
 - item 0
 - Group 1
 - - Item 1
 - - Item 2
 - Group 2
 - - Item 3
 - - Item 4
 - - Item 5
 - - Group 3
 - - - item 3
....
etc

I have tree tables in my database:

• Items - Table with items, which have colums: id and parentId, where parent id is always groups.id
• Groups - Table with groups, there records also have id and parentId, where parentId can be linked with other groups.id, but not items.id
• Tree - Table discrabes structure:
  • id - just unique key
  • parentId - parent record
  • childId - child record linked as sub-item to item from parentId
  • kind - who is childId, 0 - item, 1 - group. ParentId - always groups.
  • {possible} state - expanging state of the child group

That's.

I need good way to visualize that structure in my aptication.
Yesterday (and also a lot days before that) I see visualization, where I will build tree using clear SQL-requests, with temporary objects of records and etc.
But I found VirtualDBTreeEx component, that can made coding more professional and easy, also not so crazy.

Who worked with that component? Does anybody have example where you use that component? No documentation (Or it written in spanish), no demo-apps. Only sources...

Please help me understand that component. How to make good DB structure that will work with it. Or may be you know more useful ways to visualize tree-structured data from database?