This is the method I use to archive stuff It's just a process I follow to avoid getting myself confused:
1 create a folder on the Humax - I called mine "!Move + Delete" (the "!" puts it at top of the list)
2 move/copy selected items to the new folder - it is the same drive, so it will move (indicated by the caption next to the red button icon) This is usually instant provided you are not already copying or deleting, when it get queued.
3 with all the files you want to "move" in the special folder select the files for each given destination using up/down or the red and green buttons
4 move/copy - if it is an external drive, it will be copy, and navigate to the desired folder.
5 when all the files have been copied, go into your new folder, select all (green button) and delete.