How to read multiple values from the prompt variable to assign as default values

Hi ,

Can you please help me on this,

DS_1.setFilter("Cities", ["C001","C004","C006"]);

Hard coding these values with above code is working , but as per requirement we should n't hardcode due to later requirement changes ,instead need to read the values and then setfilter.

HANA calculated view  is used in the design studio which is  having prompt variables which were having only one default value can be assigned to  variable on starting function with out issue, but the variable which is having multiple values giving problem to assign ,for example I have 00city variable which is holding (C001, C004,C006), these default values  need to be assigned to the prompt dialog variable  "city " when the dashboard start.

I tried  something like below with  forloop code

var citycodes=DS_1.getVariables("00city");               // variable which is holding C001,C004,C005

var arraycity = "";

   citycodes.forEach(function(element, index) {

       arraycity=arraycity+element.externalkey;

   });

DS_1.setFilterExt("Cities", vcity);

but it is not  showing/assigning the values when we start the report.

Thanks for your help in advance and please excuse ,in case if I did any mistakes while posting  question.

Regards,

Kumar.