Gnus group buffer presentation

Question

In many many Gnus screenshots, I see this kind of presentation for the Group buffer:

[groupname1 -- 3]
    2: subgroupname1
    1: subgroupname2
[groupname2 -- 6]
    6: subgroupname1
    0: subgroupname2

(ex: http://zarb.org/~gc/img/gnus-screenshot-1.png or http://ostatic.com/files/images/Gnus-%5B2%5D.jpg)

I want to set this up but I do not know how or where to search. Do you have any clue how to reach this result ?

Answer 1

'Topic' is the catchword.

In the Group buffer try 't' and 'T?' for a start.

Then you may want to study (info "(gnus) Group Topics").