gnus-ham-process-destinations

gnus-ham-process-destinations is a variable defined in `gnus.el'.
Its value is

nil

Documentation:
*Groups in which to explicitly send ham articles to
another group, or do nothing (the default). If non-nil, this should
be a list of group name regexps that should match all groups in which
to do ham article moving, associated with the destination
group or nil for explicit ignoring. This only makes sense for
mail groups, and only works in spam groups.

You can customize this variable.