You can export data out of OTM using DB.XML method. its cleaner than using CSV and you can also retrieve required child records along with parent.
For example : to retrieve Shipment and associated shipment_stop records , use below query in DB.XML Export option
Query :
select shipment.*,cursor(select * from shipment_stop where shipment_stop.shipment_gid=shipment.shipment_gid) as shipment_stop from shipment where shipment_gid in (’ABC.1001’,’ABC.1002’)
Root: SHIPMENT