The ability that allows teachers to see grades according to group is missing in 1.8 beta.

In previous versions, e.g. 1.6.2+ when clicking on 'Grades' in the admin block, there was a pull-down menu that appeared to the right of the [ Download in text format ] button and listed all the groups in the course. This menu is missing.

It is possible to add &group=### to the end of the URL, so the functionality exits but not the interface.