Axis: descendant
ElementNode-set
AAA id = a1b1 b2
BBB id = b1
BBB id = b2
AAA id = a2b3 b4 c1 c2 b5 c3
BBB id = b3
BBB id = b4
CCC id = c1c2
CCC id = c2
BBB id = b5c3
CCC id = c3