gnus-move-split-methods

gnus-move-split-methods is a variable defined in `gnus-sum.el'.
Its value is

nil

Documentation:
*Variable used to suggest where articles are to be moved to.
It uses the same syntax as the `gnus-split-methods' variable.
However, whereas `gnus-split-methods' specifies file names as targets,
this variable specifies group names.

You can customize this variable.