Out of the box the grloader cannot handle customized fields for CI relations.
As far as I know the grloader uses web services methods. Does this mean that it is not possible with web services to move data from customized fields into the business_management table?
Or is it a restriction from grloader by itself?
Release: 12.9 or higher
Component: CA Service Desk Manager
You can add custom fields (String, SREL....) to the bmhier object through Schema Designer and create an entry that populated those fields via a createObject SOAP call. This is a limitation with grloader not web services.