I’ve just completed a draft of the new codex page for
BP_Group_Extension, which has been rewritten for the upcoming BP 1.8 release. Here’s where it’s currently living: http://codex.buddypress.org/group-extension-api-1-8-draft/. After 1.8 is released, http://codex.buddypress.org/group-extension-api/ will be replaced with the new page, and the old content moved to its new home http://codex.buddypress.org/developer/plugin-development/group-extension-api-prior-to-bp-1-8/
If you’ve worked with
BP_Group_Extension before, please dive into this new documentation to make sure it makes sense from a dev’s point of view.