Access of tree items through Get_DataItem

Hi all,

I previously dealt with Data Trees in the grasshopper scripts, however I am new to GH Stucture. I want to access data within a gh_structure the same way I used to within Data Trees (Tree.Branch(0)[0] for example). I fell upon the function Get_DataItem(), I assume it is the equivalent, however they require a path (GH_Path path). Under what form should the path be? Can anybody give me an example? 

Thanks