In PWA ADmin, there is a function to manage views. Either create or modify
a view to filter on "Milestone equals Yes" down in the filter section. I
don't think "Milestone" actually has to appear in the view, either.
Alternatively in Project Center, if an existing view already has the
Milestone field in it, you can filter there, and "Save Link...". Sort of a
poor-man's way to mange views! :>)
Hope this helps ...
JC