If i search for "subject:ABC" only my local folders get searched not my shared folders. What would be the root folder so i could search for "under:ROOTFOLDER subject:ABC" to find all messages also those in the shared folders?

I have a workaround because if i move the shared folders to the inbox and then search "under:inbox subject:ABC" every shared folder is searched also. But i and also my coworkers don't want every shared folder inside the inbox folder they want it on the same level.

Is this a bug ?!? If so i would file it in bugzilla.