I want to ask how to disable redirect to this page after you create a group

Hi, Ivajlo.

You can't do that via administration panel. The only way to change it is to hack core files.

Core hacks are not recommended nor supported as they may not working with future JomSocial releases and/or cause issues that will be not supported. Users with core files hack refuse to upgrade their installation to keep those hacks and they are stuck with outdated and unsupported versions.

But if you insist to change that behavior, please, consider asking professional developer for help:

www.jomsocial.com/jomsocial-developers