Nesting groups?

Can groups be nested? I tried it but it didn't work, and I don't see any examples in the standard templates.

More details: What's happening is that *every* album is being listed under *every* top level group. Within each top-level group, the albums are correctly being grouped by the second-level grouping, but they are not being restricted to those that match the top-level grouping.

Example: supposed I have two albums in my database, of different genres and different artists, and that my groupings are by Genre and then by Artist Sort. Then I should get

Genre 1
Artist 1
Title 1
Genre 2
Artist 2
Title 2

but I'm getting

Genre 1
Artist 1
Title 1
Artist 2
Title 2
Genre 2
Artist 1
Title 1
Artist 2
Title 2

My code is below.

<!--[Group($GROUPBY)]-->
<h2><!--[GroupField]-->??<!--[/GroupField]--></h2>
<ul>
<!--[Group($GROUPBY2)]-->
<li>
<b><!--[GroupField]-->??<!--[/GroupField]--></b>
<ul>
<!--[Album(all,$SORTBY1,$SORTBY2,$SORTBY3)]-->
<li><!--[ShelfID]-->?-???<!--[/ShelfID]--> - <!--[AlbumPageLink]--><!--[Title]-->Title<!--[/Title]--><!--[/AlbumPageLink]-->
<!--[/Album]-->
</ul>
</li>
<!--[/Group]-->
</ul>
<!--[/Group]-->

A little bit late response :-[ : nesting groups are not currently supported. This is the feature that will be allowed in future version.