<source> <AAA id="a1" pos="start"> <BBB id="b1"/> <BBB id="b2"/> </AAA> <AAA id="a2"> <BBB id="b3"/> <BBB id="b4"/> <CCC id="c1"> <CCC id="c2"/> </CCC> <BBB id="b5"> <CCC id="c3"/> </BBB> </AAA> </source>
<H3 style="color:blue">CCC (id=c1)</H3><H3 style="color:blue">CCC (id=c2)</H3><H3 style="color:blue">CCC (id=c3)</H3>
<H3 style="color:red">CCC (id=c1)</H3><H3 style="color:red">CCC (id=c2)</H3><H3 style="color:red">CCC (id=c3)</H3>