How can I get the filename for the extended template's filename?

[bs-thomas]

To get the current template filename, I use _self directly.

I was wondering how I can get the filename for the extended template's filename. Is there a variable like _parent or something?

Thank you very much!

[stof]

Note that _self returns the template name, not the filename (which might be totally unrelated when using something else than the FilesystemLoader, and only partially related when using FilesystemLoader with a namespace).

What is the use case for accessing the name of the parent template ?