Provide a macro setting entry as @parent (similar to @self)

In some macros such as Page Tree, it is possible to nominate the starting page using codes as @self or @home
It would be very useful to have an extra one as @parent which simply refers to the parent of the page where the macro is located

I hope that is not hard to do?

It would be super helpful if that could be added as a "patch" to previous versions of Confluence rather than waiting for the next version release - I guess that might be asking too much?