Modules: Panels

Hi, sorry if this is a not right place, but I need urgent help with group page modifications.

The problem: I need to add a panel to a group page. Group page means each page showing the content (postings) of a group (with url like: site.org/groups/my-interesting-group ). All I found is place where I can modify panels and content for Groups Directory (i.e. page with url like: site.org/groups) and I cannot locate place where I can edit panels on single group page.

Please help? Or redirect me to the appropriate place.

Best
VooVeek