ServiceNow Accessing the import_set api in a Transform Map Script 

link: https://developer.servicenow.com/dev.do#!/reference/api/utah/rest/c_ImportSetAPI

how you could loop through target records in an onComplete t-map script:

(Change the staging table name to your import set table, or alternatively use sys_import_set)

var grST = new GlideRecord('x_cls_clear_skye_i_eon_hr_import');

grST.addEncodedQuery('sys_import_set.number=' + import_set.number);

grST.query();

while (grST.next()) {

gs.warn('row--' + grST.sys_target_sys_id);

}