how to enable automatic sharing of folders added/created in an already shared folder hiearchy?

[PGNet Dev]

I'm running

        dovecot --version
                2.3.11.3 (502c39af9)

folder sharing is enabled & working.

as long as I manually enable enable sharing for each folder/subfolder.

e.g., if I enable sharing for each of:

        sharedtopfolder
                subfolder1
                subfolder2

then all's good -- shared-to users can access according to set permissions.


BUT, if I drag any folder under that shared-hierarchy

e.g.,

        sharedtopfolder
                subfolder1
                subfolder2
+                       subfolder3
+               subfolder4

the just-added

        subfolder3
        subfolder4

are NOT shared.

They CAN be -- manually. And, as soon as they are, they're, again, usable by 
target users.

I'd like to have any/all newly-created, or dragged-in, folders under the already-shared 
"sharedtopfolder" to
be **automatically** enabled for sharing.

how is that explicitly setup?

is it 'just' Dovecot config?
&/or does it require some Sieve?