var ScriptIncludeName = Class.create();
ScriptIncludeName.prototype = Object.extendsObject(AbstractAjaxProcessor, {
getUniqueCostCenters: function(){
	var ccList = [];
var uniqueArr = [];
var ids = [];
var arrayUtil = new ArrayUtil();
var cc = new GlideRecord('cmn_cost_center');
cc.query();
while(cc.next()){
  ccList.push(cc.name);
}
uniqueArr = arrayUtil.unique(ccList);
uniqueArrFinal = uniqueArr.join();

ccList = "";
var cc1 = new GlideRecord('cmn_cost_center');
cc1.addEncodedQuery('nameIN'+uniqueArrFinal);
cc1.query();
while(cc1.next()){
  ccList=cc1.sys_id+',';
}

return 'sys_idIN'+ccList;
},
	
    type: 'ScriptIncludeName'
});

This should work now please try it and lemme know 
Mark the response as correct if that really helps 

Thanks
Siva