Actually, now that I have tried it, here's a couple of options.
In Opus perform a Find (Ctrl-F) with the Folders Only filter applied in the Advanced Panel. With the results displayed, Edit --> Copy Full Pathnames (Ctrl-Shift-C) and paste into Excel to get what you want.
In Everything, search with type:folders then Select All then File --> Copy Full Name to Clipboard (Ctrl-Shift-C) and paste into Excel to get what you want.