I have gone through other questions as well, but couldn't figure out something. I want to create a User list using the Expandable RecyclerView. The way I want it to be
My RecyclerView part is all done. Now my question is how can I achieve this expandable RecyclerView part programmatically. And if I can do this using any library which one would be best to use.

You can use this library to achieve expandable recyclerview.
https://github.com/thoughtbot/expandable-recycler-view