How to add subgrid in parent grid

[preety2]

I want to add click on arrow and subgrid open but if we can do row click its also fine.
I added row render but its effect on parent row.
I used this code
http://jsfiddle.net/9ftwLsmf/

I want to add only subgrid on exiting grid.

[quidlab]

check out this
https://jsfiddle.net/jay9r7uv/1/