Variable: msb-max-file-menu-items
msb-max-file-menu-items is a customizable variable defined in
msb.el.gz.
Value
10
Documentation
The maximum number of items from different directories.
When the menu is of type file by directory, this is the maximum
number of buffers that are clumped together from different
directories.
Set this to 1 if you want one menu per directory instead of clumping them together.
If the value is not a number, then the value 10 is used.
Source Code
;; Defined in /usr/src/emacs/lisp/msb.el.gz
(defcustom msb-max-file-menu-items 10
"The maximum number of items from different directories.
When the menu is of type `file by directory', this is the maximum
number of buffers that are clumped together from different
directories.
Set this to 1 if you want one menu per directory instead of clumping
them together.
If the value is not a number, then the value 10 is used."
:type 'integer
:set #'msb-custom-set)