For status updates, to the left of the share button there's a dropdown menu where you can customize who can see it.
If you're trying to write on someone else's wall, but only want certain people to view it, you're better off sending a message instead. You can send a message to a list by just typing in the name of the list in the 'to' field.
You can customize who can see any album in the edit album info tab, and selecting the privacy dropdown and clicking customize.