CRM: BPATH- sorting
If you want to sort on your BPATH statement, the explanatory article by SAP provides an example that starts from the root node. So if you want to sort a subnode (say to return the standard phone number (irrespective if it's mobile or landline), do it as follows:
BuilStandardAddressRel/BuilStandardAddressPhoneRel/~*[!STD_NO:DT,*]/@CALLER_NO
Explanation: