hierarchy data structure

hi

I have an Hierarchy Data Sructure in my API, I'm using that API with Kendo react react treelist , now the tree list is working fine but i can't get the data from last index position, now I'm able to only get the index position, how can i get the data from my API.

Example below:

- Item 1

         - Sub Item

                        + Inner Sub Item

+ Item 2

+ Item 3

+ item 4

my question is how can i get the Inner Sub Item  from the Treelist :)