How to browse gmane hierarchy?

[JibStyle]

Hi, I have configured Gnus with NNTP server news.gmane.io. When I press
M-d in the group buffer, it lists about 36k groups. I would like to
browse and subscribe to some groups, but I don't have time to linearly
scan through this list. The group names follow a hierarchical naming
pattern. How can I browse groups in a hierarchical fashion? Thanks.