Last one may not work, This was tougher than I thought, I would really suggest you control the duplicate names at the table level for cost center, This is really not a recommended approach.
I have tested this script and it works, Please try this out
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.toString());
}
uniqueArr = arrayUtil.unique(ccList);
ccList = [];
for(var i=0; i<uniqueArr.length; i++){
var cc1 = new GlideRecord('cmn_cost_center');
cc1.addEncodedQuery('nameIN'+uniqueArr[i]);
cc1.query();
if(cc1.next()){
ccList.push(cc1.sys_id.toString());
}
}
return 'sys_idIN'+ccList.toString();
},
