Is there a way to have an optional TBS Sub Block?

Question

I have a word document and I was wondering how I can still print out the states even if I have nothing for cities. Lets say for California I have 20 cities, but for Texas I still don't have any entries.

 [state;block=begin;sub1 = cities]
   [state.State] 
       [state_sub1;block=begin]
          [state_sub1.City]
       [state_sub1;block=end]
 [state;block=end] 

Answer 1

[state;block=begin;sub1 = (cities)]