For the moment the only thing that you can do is name "each object" and select them as you want in the Menu Objects!
(for don't forget someones on direct selection on the screen! )
So make a list of name ordonned like this
ArmLeft01
ArmLeft02
ArmLeft03
ArmRight01
ArmRight02
ArmRight03
etc...
and even this list will be not incemented with offset on The Object dialog!

Maybe on the V 4 that will be more elaborated who knows... :)

PS You can make a sort of "one Level" of "SubObject" if you give a Style Color to a selection of Objects named!
For example
Select
ArmLeft01
ArmLeft02
ArmLeft03
and give them a Color Blue

So now when you select the Color Blue, your ArmLeftn are selected without lost their own names!

That is not the case when you select
ArmLeft01
ArmLeft02
ArmLeft03
ArmRight01
ArmRight02
ArmRight03
and name them Arms!!! Original names are losted!!!

Posing Kinematics is not yet implemented! Maybe with nodes Elephant?...I don't remember seen that...