Possible to disable dashboard access?

Ok. I don’t get it… I’m new to myopenhab and want to use the dedicated expose feature to only give access to a few light bulbs. I don’t want to give myopenhab control over all items via the dashboard/sitemap.
Is there an chance to build it this way?
I’ve filled in only one item fore testing under “expose”. This item shows up in myopenhab. But if I do click on dashboard, I can control EVERYTHING.
Is this by design? And if not… what am I missing?

Did you have any success?

I belive this is the answer: