Find the list of values for an EntityProperty qualifier?

Questions
,
1

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I have an EntityProperty and I know how to get its list of qualifiers. Now how do I figure out the possible values these can take programmatically? Here’s an example to get us started:

EntityValue[
 EntityProperty["Country", "ExternalBalance"],
 "Qualifiers"
 ]

{"CurrencyUnit", "Date", "PercentOfGDP", "TradeSection"

Now, say, how do I programmatically determine what "CurrencyUnit", "TradeSection", and "PercentOfGDP" can be?

2

Enumerated qualifier values can be looked up using “QualifierValues”:

In[1]:= EntityProperty["Country", "ExternalBalance"]["QualifierValues"]

Out[1]= {"CurrencyUnit" -> {"Constant2000USDollar", 
   "Constant2005InternationalDollar", "ConstantLCU", "CurrentLCU", 
   "CurrentUSDollar"}, "Date" -> {}, 
 "PercentOfGDP" -> {"PercentOfGDP"}, 
 "TradeSection" -> {"GoodsAndServices"}}