[Yum] Repositry precedence

[Marc Glade]

I'm wondering if it is currently possible to have yum select the latest
version of a package from one group of repositories over another group
of repositories? I think what I am envisioning is some sort of new
tiered approach to the repositories in yum.conf that mixes
pkgpolicy=newest with pkgpolicy=last that isn't currently doable with
yum. Say I have 3 repositories in tier A and two more in tier B, when I
run yum to update or install a package I want yum to search tier A first
and if it finds the correct package to pick the latest from those 3
repositories. If it cant find the package in tier A than it would search
tier B. This would allow me to keep packages that may not be the newest
out of all the repos in my yum.conf but are the newest from the repos I
have more trust in or prefer to use over others whenever possible. If
this is already possible with yum can someone point me in the right
direction on how to set this up.

Thanks,
Marc

-- 
Marc Glade <mglade at gladeweb.com>