Hi Andrew,
Further to my previous comment, if your data source is a Universe or if the currency dimension is being filtered, getMembers("DimensionName", 0) may in fact retrieve the desired result. In this case, to test the assignment of the value of the currency symbol to a global script variable, instead of looping through the array, you can simply apply the following more condensed script code:
var myCurrencyDimensionMember = DS_1.getMembers("CURRENCY_SYMBOL", 0)[0];
myCurrencySymbol = myCurrencyDimensionMember.internalKey; // Global Script Variable
If you need the currency text you can apply the following:
myCurrencySymbol = myCurrencyDimensionMember.text; // Global Script Variable
Regards,
Mustafa.