Yes, this is available in the current version although it's currently
undocumented because I wasn't really happy with the syntax. Right now
it requires you to know the moduleId of the Aggregator and the moduleId
of the module you want to show. The syntax is shown below.

Basically, you need to add a query string parameter to the page url
that is formatted as
Module[AggregatorModuleId]_SelectById=[ShowModuleId], where
[AggregatorModuleId] is (obviously) the Aggregator ModuleId and the
[ShowModuleId] is the ModuleId of the module contained in the tab you
want to show. To determine the moduleid for each module, just go into
module settings for that module and you'll see ModuleId=xx in the
address bar. Like I said, it's a bit clunky for my liking right now so
the syntax may change in the future but I'll attempt to keep this
syntax around for backward compatibility. Also, if you have more than
one aggregator on the same page, you can specify each individual
parameter using the ampersand syntax &.

For this sample, the Aggregator module (ModuleId = 343) would select the tab containing the module with ModuleId=4.

    Default.aspx?Module343_SelectById=4

Of course, to move to the proper DNN tab, you'll have to add that in as well so you'll have something like,

    Default.aspx?Tabid=123&Module343_SelectById=4

Edit: As of 4.5.x I have added two other ways to do the same thing: SelectByNum and SelectByTitle. SelectByNum takes a tab number argument and SelectByTitle takes a text argument.

Examples:

    Default.aspx?Module343_SelectByNum=2     will select the 2nd tab

    Default.aspx?Module343_SelectByTitle=Features     will select the tab with caption entitled 'Features'