filesets-browse-dir-function is a variable defined in `filesets.el'.
Its value is
dired
This variable may be risky if used as a file-local variable.
Documentation:
A function or command used for browsing directories.
When using an external command, "%s" will be replaced with the
directory's name.
Note: You have to manually rebuild the menu if you change this value.
You can customize this variable.