I noticed that if you use the 'hostname contains' filter and then only part of the hostname 'server' (say full hostname is serverA.zone.mycompany.net), it will not find any hosts.
It looks like hostname is parsing the FQDN into parts (serverA, zone, mycompany, net) and then applying the contains filter to each of those instead in it's entirety instead of doing adding a wildcard like server*. If I do server* as my filter parameter, it works fine.
I just wanted to check if this is expected behavior. I validated this in 2.5TP2 and 2.0GA.