//*[count(*)=3]
Select all elements which have three childrens of any type//*[count(*)=3]
... <aaa> <bbb> <ccc></ccc> <ccc></ccc> <ccc></ccc> </bbb> <bbb> <ccc></ccc> </bbb> </aaa>
Select all elements which have three childrens of any type//*[count(*)=3]
... <aaa> <bbb> <ccc></ccc> <ccc></ccc> <ccc></ccc> </bbb> <bbb> <ccc></ccc> </bbb> </aaa>