I had to switch from "sieverules" to  "managesieve" to enable the 'filters' menu in roundcube.
DetailsI installed roundcube as described in the wiki at 
RoundCube:
yum install smeserver-roundcube --enablerepo=smecontribs
signal-event post-upgrade; signal-event reboot
After installation and reboot I did not see any "filters" menu  in "settings".
The roundcube config looked like this:
config show roundcube
roundcube=service
    DbName=roundcube
    DbPassword=333983493809686
    DbUser=roundcube
    Name=RoundCube IMAP Client
    PluginsList=globaladdressbook,contextmenu,markasjunk2,vcard_attachments,newmail_notifier,emoticons,sieverules
    PublicAccess=global
    status=enabled
I switched to the other sieve plugin 
mentioned in the wiki:
config setprop roundcube PluginsList globaladdressbook,calendar,libcalendaring,contextmenu,markasjunk2,vcard_attachments,newmail_notifier,emoticons,tasklist,managesieve
signal-event roundcube-update
Now I see 'Filters' under 'Settings'.