Can project.el or projectile.el help? How about completion?

[John Yates <john@yates-sheets.org>]

I work on a large corporate mono-repo in which numerous
filenames occur repeatedly.  Further, various directories
above such duplicates also have duplicated names.

Currently I use a self-built emacs tool to index this space:
* Build a map from a unique filename to a set of
  repo-relative directory paths to files with that name
* Compute a disambiguation string for completing reads
  for unique filenames this string is empty; otherwise:
  * Repeatedly strip identical leading directories
  * Repeatedly strip identical trailing directories

I would like to replace this tool with something like
project.el or projectile.el.  So the first question is does
either package do anything intelligent when filenames
are duplicated?  If so, what?

Then, is there any completion package that can present
the candidates in an order reflecting their distance from
the current buffer's working directory?  My thought is to
sort identically named candidates by their repo-relative
paths.  A focused, incrementally widening presentation
of candidates would show initially those in or below the
current working directory.  Each time instructed to widen
the presentation it would advance up the parent directory
chain, showing candidates in or below that directory.

/john