How do I view the hierarchy of which Unit USES another? (Delphi)

There is a large project, and I need to see the hierarchy of Units which each file references in it's USES clause.

ex.

                                Project Source (program.dpk)

        HelperUnit                  Forms                ThirdPartyUnit

MyUtils MyConsts MyDownload                         TPShellShock  TPWhatever 

How can I see this dependency tree of sorts? I remember there being some feature like this in one of the newer Delphi versions, but I don't remember what it was called. It may have been a plugin.

Any hints on how to do this would be great. I started writing my own program to do it but I've already wasted like 3 hours and am still working on the parser for pas files.

There also is a unit dependancy analyzer built inside of GExperts. Look for the option labled "Project Dependencies". This does work from an expert within Delphi against the currently loaded project.