Buddypress - Post visibility related to group

I am pretty new to buddypress. I am trying to do something pretty simple in Drupal/Organic group.

Create a Group X.
Create a post with an additional attribute called "audience". That should have the group name as possible value e.g. Group X.

I want that people that belong to Group X can see the posts marked with audience= Group X. As far as I can see the only way to do it is to create a new blog in a multisite installation. But to me seems an overkill.

Can you give me some suggestions on how I can achieve this?

Solution

Well, I'm currently working on that, just adding an extra page to Groups and then showing there the posts that match the category that I have selected.

For learning how to add pages/tabs to groups here is the documentation: http://codex.buddypress.org/developer-docs/group-extension-api/

But if you don't feel confident enough there's a free plugin that lets Group admins associate blog categories with a group: http://buddydev.com/buddypress/blog-categories-for-groups-plugin/

Hope I have helped you even though your question was asked long ago :P. Regards