Subfolders

[boxofgit]

Is there any way to have a bit more control over the folder view "layout"?
I'd like to have for instance one first folder view with:

INBOX
Important
Sent
All
Spam
Trash
Draft

And group other messages tagged with other "labels" within "All" folder.

All
|___ tag-a
|___ tag-b
|___ tag-c
|___ and so on

By select "All" folder and pressing I'd like to show a second folder view (let's say a "subfolder view") containing all messages sotred by tags "a, b, c, and so on". Here, after select for instance "tag b" subfolder, we will show listo of message tagged "b".

I'm trying to use lieer and notmuch-vim to manage a GMail account, with labels untouched. Notmuch-vim is really fast, really good!
But my GMail labels appear a bit too "intrusive"... I'd prefer a folder view with just the above folders visible (INBOX, Sent...) and the others GMail labels grouped within a subfolder that I named as "All" in my above example.

Would be possible to achieve such a config?
Thanks a lot for this beautiful plugin!