//*[name()="ddd"]
Select all elements of type "ddd" (equivalent with //ddd)//*[name()="ddd"]
... <aaa> <bbb> <ccc> <ddd id="1">this</ddd> <eee id="2"></eee> <ddd id="3">this</ddd> <fxf></fxf> </ccc> </bbb> </aaa> ...