The getSubrecord() method is used to get the address book fields from a specific field subrecord.

The script code is used as below.
let subRec = record.getSubrecord({ // Here the record must be the record obj of the required record
fieldId: ‘billingaddress’
});
let addLabel = subRec.getValue({ fieldId: ‘label’ });
let addressee = subRec.getValue({ fieldId: ‘addressee’ });
let addressOne = subRec.getValue({ fieldId: ‘addr1’ });
let addressTwo = subRec.getValue({ fieldId: ‘addr2’ });
let country = subRec.getText({ fieldId: ‘country’ });
let city = subRec.getValue({ fieldId: ‘city’ });
let state = subRec.getValue({ fieldId: ‘state’ });
let zipCode = subRec.getValue({ fieldId: ‘zip’ });
We can handle these data as per our requirement.