Your match
attribute has to match
a node, but you are performing a test in it which does no return a node (but a boolean result).
You could change it for it to match a node, placing the second part of your expression inside a predicate testing the current node. Perhaps this is what you want:
STEP[STEP_ATTRIBUTE='Step Name'][node() = concat('tenants', $apos, ' A ', $amps, ' A works')]