In the group buffer typing G G will search the group on the
current line by calling
gnus-group-make-nnir-group. This prompts
for a query string, creates an ephemeral
nnir group containing
the articles that match this query, and takes you to a summary buffer
showing these articles. Articles may then be read, moved and deleted
using the usual commands.
nnir group made in this way is an
ephemeral group, and
some changes are not permanent: aside from reading, moving, and
deleting, you can't act on the original article. But there is an
alternative: you can warp to the original group for the article
on the current line with A W, aka
gnus-warp-to-article. Even better, the function
gnus-summary-refer-thread, bound by default in summary buffers to
A T, will first warp to the original group before it works its
magic and includes all the articles in the thread. From here you can
read, move and delete articles, but also copy them, alter article marks,
whatever. Go nuts.
You say you want to search more than just the group on the current line? No problem: just process-mark the groups you want to search. You want even more? Calling for an nnir search with the cursor on a topic heading will search all the groups under that heading.
Still not enough? OK, in the server buffer
gnus-group-make-nnir-group (now bound to G) will search all
groups from the server on the current line. Too much? Want to ignore
certain groups when searching, like spam groups? Just customize
One more thing: individual search engines may have special search
features. You can access these special features by giving a prefix-arg
gnus-group-make-nnir-group. If you are searching multiple
groups with different search engines you will be prompted for the
special search features for each engine separately.