define(['N/record'], function(record) {
  function afterSubmit(ctx) {
    var recType = ctx.newRecord.type;
    var recId = ctx.newRecord.id;
    //careful not to name the new variable record, because that would replace the reference to the N/record module
    var rec = record.load({ type: recType, id: recId });
    // now get the fields you want from rec that aren't in ctx.newRecord
  }
  return {
    afterSubmit: afterSubmit
  };
});