Any suggested model to perform semantic linking?

Hi Guys, I am new to NLP field, and currently I am working on an Form Understanding project, I have applied OCR and LayoutLM to get the entities with their labels(e.g. question, answers, others etc.), but I found layoutLM does not provide the semantic linking to link the question with its corresponding answer(and the LayoutLM paper also mention semantic linking is not the focus), in this case, May I know which transformer model and downstream task could be used for semantic linking? any suggestions will be greatly appreciated. thanks!