Parent child node in result

My `Requirement is " According to section (A , B , C ) ,the student names should display .For Example , Under A section , The students name belong to A section should display .

In source side , I will give as Name , ID , Section.

Everything I did , but exept this .

I'm getting like , A section under 1 student name , ID and again displaying Section A (I don't need this) under another student name , ID etc .

Similarly for B sec and so on . Please kindly help me with this issue