The short answer is "no" :-)
The longer answer is ...
There
are a couple of reasons why we decided against multi-level folders. The
first is that we couldn't find a visual representation that didn't end
up burying notes such that they became hard to find. Secondly, we wanted
to be portable to a variety of back-end storage services. Google Drive
supports nested folders, but there may be a future service that we need
to support that does not.
To
compensate for the lack of nested folders, we are focussing on tags and
virtual folders as a mechanism by which users can construct a taxonomy
to precisely suit their needs. So for example, if you search on
"tag:foo" (or "#foo" as a shorthand), we construct a virtual folder
called "tag:foo" containing the results which then behaves like a
folder. Also, currently in staging at
http://foo.clever-note.appspot.com, we have implemented a Kanban view (think "Trello"), which provides a drag and drop mechanism for organising notes by tags.
I
hope this gives you the tools you need. If not, please let us know a
bit more about your use case and we'll look into what additional tools
we can add.