Unable to sort in Opportunities module when drilling down via dashboard

Hi all

Scenario: when on a dasboard that has graph filter, click on one of the pillars to get the details. At this point, I am unable to sort (you can see there are no arrows in this picture):

As appose to the "regular" view. Here is a picture of regular filtering - here you can see the arrows (to sort on):

Thanks,

KGM