It can be. The general discipline is industry knowledge, but the company's own failure-mode library, thresholds and scheduling method are proprietary, and the planner's knowledge of those is what L-1B recognizes.
Distinguish the discipline from the company's implementation of it
Reliability-centred maintenance is a recognized discipline, and an officer will not accept that knowing it is specialized. The Torbay petition must therefore be precise: the specialized knowledge is of the petitioner's failure-mode library built from eight years of its own site data, the condition-monitoring thresholds it has calibrated for particular equipment fleets, and the scheduling algorithm it developed, none of which is available outside the company. The planner's knowledge is advanced because the planner authored much of the library and trains others on it. Evidence should include the library itself or representative extracts, revision history, the training curriculum, records of who has completed it, and a comparison explaining what a competent planner hired in the United States would not know. The other requirements are unchanged: a continuous year with the Torbay company in the last three, a qualifying subsidiary relationship with both companies active, and a U.S. role that actually uses the specialized knowledge rather than general planning.
Hypothetical example: a Torbay industrial-laundry equipment company wants to transfer a technician who knows the same published sanitation standard as many competitors. The standard alone is not specialized knowledge. The decisive record would be the company's private commissioning matrices, controlled revisions and proof that the technician developed or taught their use. A first review separates what is public industry skill from what belongs to the petitioner; without that distinction, calling the technician essential does not answer the legal question.