* Heading A

** Subheading AA

*** Subsubheading AAA

Stuff about topic AAA

*** Subsubheading AAB

Stuff about topic AAB

** Subheading AB

*** Subheading ABA

Stuff about topic ABA

*** Subheading ABB

Stuff about topic ABB

* Heading B

** Subheading BA

*** Subheading BAA

Stuff about topic BAA

How can I make it so that on startup, only the content of the first "leaf" heading is revealed, so that the document looks like:

Shankar Rao