Yes, that's the basic code to output the activity for groups you are a member of - but you need to wrap that in a page, and have it in the context of the 'activity', and some way to navigate there - presumably a tab

i made a plugin to resolve this issue in elgg 1.7 - there is a dropdown selector added to the river activity filter selector area that lists all groups you are a member of. the river is updated to view only data for that group when you choose a group in the list.

matt's code, as far as i am aware, produces the same output as choosing show groups in the existing river dropdown in elgg core - except it will appear in the location you add it to, rather than in the default river.

i am also interested to extend these features in 1.8..
what i'm looking for really is a way to duplicate what i did in 1.7 but with simpler code.. i think the code matt has shared here inspires me to look again as i didn't know elggs structures well when i wrote the 1.7 plugin.

You are giving me hope Ura ! :)

And thanks Matt. Your code seems to have set things in motion.