Different types of groups with different nodes(tabs)

A orgainc group may have serveral nodes as following:

The View, Oveview, News are group eBEREA Management board's nodes.

These nodes are managed by Views, you can check them in admin/site building/views

Use lectures view as an Example:
All nodes here is a menu item likes 'node/%/news' in fact, and the type is MENU_LOCAL_TASK

Click Edit link, we can see the following panel:
The Arguments is set to select which kinds of node this Lectue tab could be seen.
If we want Lecture tab to be seen only in content type Course, a organic group content type, we set the arguments like following:
1, add new arguments, select Groups: Organic groups, Organic groups: Groups, click Add


2,the validator options, Validator: Node, Types: Course, click Update3, Don't forget to click Save Button