Sven Weller shows on in https://svenweller.wordpress.com/2018/05/17/plscope-fetch-module-name-from-line-number/ how to calculate submodule names (e.g. functions within functions within functions) using a dot notation.
This information should be included in plscope_identifiers view as an additional column (it is different to the name_path column which provides the full name path including all identifier types).