What is the appropriate method to find n-grams/sub-phrases/parts-of-sequences that are referring to a specific topic or belong to a certain category?
Imagine a topic of "transfer of ownership" and some example sentences:
- A >change of ownership< occurs when a title is transferred from one person or entity to another
- Making a >change in business ownership< is a lengthy and complex process
- In this respect, the >transfer of legal ownership< is not the relevant feature for determining the treatment of repo-like operations
What I am looking for is a method to identify sentences and ideally parts of sentences which refer to a specific theme / topic.
What NLP methods are appropriate?