Hi Lava,
From your post it is clear that you have been able to find values for city and External Id of supplier.
You need to use API getCurrencyObjRef() for fetching the value for field id CURRENCY. Similarly you can use API getCountryObjRef() for field Id ORDER_COUNTRY. If you want to get the display name of country only you can use.
LocalizedObjectReferenceIfc supplierCountryRef= supplier.getCountryObjRef();
if(hasValue(supplierCountryRef))
{
String supplierCountryName= supplierCountryRef.getDisplayName();
}
This should work. Please let me know otherwise.
Regards,
Kumud