Is there a way to move a node up the root in HOCON?

I'm using typesafe config and I'm looking for an easy way to allow optional overrides of properties in config files that are shared between applications.

So lets say I have 2 apps, A & B. They both make use of a module Z. They both load a shared config file 'shared.conf'.

Module Z has a property defined in it's reference.conf

z.foo=bar

I'd like to be able to

#override the property for both A & Bz.foo=zap

or

#override the property for just Aa.z.foo=zip

I know I can do this for just the 'z' prefix in the application.conf of each app. e.g.

z = ${?a.z}

but I was hoping there might be a way to move all the way to the root node. e.g.

MAGICAL_ROOT = ${?a}

Is what I'm hoping for possible?