I just set up my multisite and everything works fine.
I can create subdomains for my main domain and map some other domains to these subdomains like:
firstdomain.com mapped to sub1.maindomain.com
seconddomain.com mapped to sub2.maindomain.com
However I could not map a subdomain of another domain to the subdomain of the maindomain. I tried everything reading the manual and playing with dns settings. I need to do this:
sub1.thirddomain.com mapped to sub3.maindomain.com
sub2.thirddomain.com mapped to sub3.maindomain.com
Can anyone please let me know if this is possible and how I shall do dns settings. I use WPMU domain mapping too and host in pSek.