[jmh2002]

Ah, no not XBMC settings, but the settings submenu.

You choose what submenus you want to show for each main menu item here:

System > Skin > Home Menu Buttons > SubMenu Set > (and choose Settings)

The items that show under the Settings submenu set can be seen here:

System > Skin > SubMenu Items > SubMenu Set > Settings

I think the default items should be: Skin Settings, Settings, File Manager, Addon Browser, Profiles, System Info

but... these are customisable too so you may have deleted the File Manager at some point?

In any case, you can add the File Manager to whatever SubMenu set you want. Everything can be customised.