Add Nested Options to Dropdown Button

[bobthebear]

I noticed in the docs that the Navigation and Checkbox Group components allow nested options using a parentValue parameter:

Would it be possible to add this to the Dropdown Button component as well?

What's above works well enough, but I was looking to organize these a bit better so I have a 'Review' and 'Help' items which expand to ["approve", "reject", "flag"] and ["Request Agent", "View Help"]

[Darren]

Great point, @bobthebear! I've documented this request internally and will let you know when we've had a chance to review it and formulate any follow-up actions.