Hi Alex,

That feature will be present on the next release... it is already implemented and working. If you use centos 5 32 bits you can download the devel version and replace the files:

http://www.fop2.com/downloads/fop2_server
http://www.fop2.com/downloads/fop2.js

In the button definition you add "group=MYGROUP" to the extensions you want and they will be presented on their own section. You can define as many groups as you want.

Best regards,

Implemented in FOP 2.10!