Creating additional tabs on "Groups"

Just like the "latest discussion" link in groups (

I need someting that can also filter the subtypes of the following object too..

1. Photos (Tidypics Photo Gallery)
2. Videos (Videos 1.4)
3. Blog (Blog 1.8)
4. Files (File 1.8.1)

So that when i go for "groups/all?filter=album" then i will be able to see all the album of every group
similarly for "filter=videos" will show all the group's videos, "filter=blogs" will show all the group's blogs and finally "filter=files" will show all the group's files.

How can this be implemented?

I am still a noob so it would be great if i get the source code. That will help me a lot.