Use XMLUseParent to indicate how the XML button determines the XML broker whose data packets it manipulates. When XMLUseParent is false, the XMLBroker property must be set to indicate the XML broker. When XMLUseParent is true, the XML broker associated with the XML button's parent determines the associated XML broker.  

The XML button's parent is the Web item (typically TDataNavigator) that uses the XML button to assemble its own HTML content. The parent's associated broker may be defined through an indirect association. For example, the data navigator acts on another component, such as a field group, which has an associated broker. 

If the parent does not have an associated XML broker, setting XMLUseParent to true sets the XMLBroker property to nil (Delphi) or NULL (C++). 

XMLBroker