I have 5 MViews that I want to refresh in two occassions, every sundays and at the 1st of the month. I created a Refresh Group for the weekly and that work fine. But when I tried to created the second Refresh Group for the monthly I get a "materialized view is already in a refresh group".

You can only have a materialized view in one refresh group? What options to I have to refresh it in different intervals?