gimp/menus/channels-menu.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE ui SYSTEM "gtkuimanager.dtd">

<ui>
  <popup action="channels-popup">
    <menuitem action="channels-edit-attributes" />
    <separator />
    <menuitem action="channels-new" />
    <menuitem action="channels-raise" />
    <menuitem action="channels-lower" />
    <menuitem action="channels-duplicate" />
    <menuitem action="channels-delete" />
    <separator />
    <menuitem action="channels-selection-replace" />
    <menuitem action="channels-selection-add" />
    <menuitem action="channels-selection-subtract" />
    <menuitem action="channels-selection-intersect" />
  </popup>
</ui>