Axis: descendant
Element
Node-set
AAA id = a1
b1 b2
BBB id = b1
BBB id = b2
AAA id = a2
b3 b4 c1 c2 b5 c3
BBB id = b3
BBB id = b4
CCC id = c1
c2
CCC id = c2
BBB id = b5
c3
CCC id = c3