Need Domain specific sieve script instead of system global

Let me ask this a better way.  Reading this file:
/etc/dovecot/conf.d/90-sieve.conf

 # The default Sieve script when the user has none. This is a path to a global
 # sieve script file, which gets executed ONLY if user's private Sieve script
 # doesn't exist. Be sure to pre-compile this script manually using the sievec
 # command line tool.
 # --> See sieve_before fore executing scripts before the user's personal
 #     script.
 #sieve_default = /var/lib/dovecot/sieve/default.sieve

It sounds like there's no way for a mail server to have a virtual domains specific sieve script.   It's either each virtual user has to have their own sieve script OR ELSE the global /var/lib/dovecot/sieve/default.sieve takes over.  This isn't very useful when you are running multiple email domains.   

I'm trying to come from a procmail environment where I can do user, domain and system-wide rules however I want.  Any ideas?

email filters per mailbox can be generated from the user panel using email filters or from the roundcube.