Hi rasmusse1,
BuddyPress enforces the rule that the very first sub-tab has the exact same slug as it’s parent, and that the parent’s contents is the contents of this very first sub-tab. The second sub-tab would get it’s own slug and show different content.
For instance, if you click the ‘Personal’ sub-tab of the main ‘Activity’ tab, it will have the slug ‘http://mysite.com/members/admin/activity/’ and will show the ‘Personal’ page. The second ‘Mentions’ sub-tab however will have the slug ‘http://mysite.com/members/admin/activity/mentions/’. The ‘Activity’ tab in this case never has it’s own individual content, and the same goes for your main tab page.
In case I missed a part of your problem, kindly attach a link to a screenshot where you’re having trouble.
Thanks,
Tarek