There is no calendar view, sadly (not for J anyway).
There is a little URL hack you can use to filter out Y, which is to do a search for whatever date you are looking for (it's easiest to do it with one way searches), then take a look at the URL and change this bit
class=First
to
class=Business
Don't change anything else, but then copy the whole URL into a new tab and hit enter (this bit is important -- it won't work if you try to reload it in the current tab).
For one way itineraries originating in Australia, unfortunately this will return all the "any seat" redemptions at 1Mill+ points, but you can at least scan down the list and if any of them show the little "reward seats available" box then there should be a genuine business award available.
It's slightly easier for itineraries originating outside Australia, because VA doesn't sell revenue tickets originating overseas. That means the search will *only* return J awards if available on that date (no "any seat"/"points plus pay"). If there aren't any awards it will drop back to an availability calendar, but sadly this calendar shows Y availability and does not respect the class=Business filter.
However, once you've changed the URL param it does "stick" within the flight-selection page, so you can click around the 7 day filter at the top to quickly check a range of dates. If you find yourself on the calendar view you can try clicking on dates that are highlighted, but if there is only Y availability on the selected date you'll drop back to the calendar again.
The other thing I do is if there are specific dates I'm looking at is to bookmark the searches (with the modified parameter). The whole of the query (dates, city pair etc) is captured in the URL params, so you can save searches as bookmarks for all the dates you are interested in and then quickly open them all up again later to see if something has become available.