I have a project A which depends on project B, and optionally, on project C.
Most of the php classes in A extend the classes of B; some extend the classes of C.
Installation is handled via Composer - projects B and C end up in the vendor/ dir.

What I am looking for, and I can not seem to find a way to achieve, is to document all the classes of A, and include in the generated docs all the members/methods/consts that they inherit from the classes in B and C.

Ideally, the docs would not include anything from B and C which is not used from A, i.e. no consts, functions, etc, which are not used by the A classes.
But I could live with a complete documentation, containing all the elements of A, B and C, as long as the elements of B and C were clearly documented as belonging to separate packages.

It seems that this is not possible at the moment. I tried using a config file, but either I have to put all directories within a single api element, and then there is only one package name in the generated docs, or I can try with multiple api elements, but then phpdocumentor throws an error saying this is not yet supported.

Also, when I put all the source code directories within a single api element, there is an issue with the generated "package index" page: while it does not list all existing classes, it only shows their name, omitting the namespace. As I have classes with the same, but different namespace, in A, B and C, the "package index" page becomes confusing.

Is there any way to achieve this?