在 Apple Script 中，可通过以下示例代码向菜单栏中添加返回功能：

on addBackMenu()
    tell application "System Events"
        tell process "SystemUIServer"
            
            -- find the first menu bar and get the menu items
            set menuBar to menu bar 1
            set menuItems to menu bar items of menuBar
            
            -- go through each menu item in reverse order and add a "Back" menu item
            repeat with i from (count of menuItems) to 1 by -1
                set menuItem to item i of menuItems
                set menuTitle to name of menuItem
                
                if menuTitle is not equal to "" then
                    set newMenuItem to make new menu item at beginning of menu items of menuItem with properties {title:"Back", enabled:true, action:"myBackFunction"}
                    set name of newMenuItem to "Back"
                    return
                end if
            end repeat
        end tell
    end tell
end addBackMenu

on myBackFunction()
    -- Handle the "Back" menu item clicked event here
end myBackFunction

该代码将在菜单栏中的每个具有标题的菜单项后添加一个 "Back" 选项。您可以在 myBackFunction() 中处理返回操作的代码。

注意：这段代码必须在脚本运行时才能够在菜单栏中显示。您可以在 Apple Script 编辑器中运行此代码。