There are five step nodes
<step1><step2><step3><step4><step5>

I need to output a number at the first occurance of a <para> within each
step, which can be as a child or within a <specpara>

There are several possibilities:
1. (step1//para|step2//para|step3//para|step4//para|step5//para)[1]
2. para[ancestor::step1 or ancestor::step2 or ancestor::step3 or ancestor::step4 or ancestor::step5][1]
and a multitide more.

HTH
J.Pietschmann