Demonstrating the level of your business analytical skills is more of a general statement in that it does not target any specific concept, but rather your overall approach to answering questions, and the resulting quality of your responses, which reflects the effectiveness of your approach. Depending on the topic(s) that your exam will cover, you will merely have to prepare for it by ensuring that you have a thorough knowledge of the content as well as the syllabus dot points, with the latter allowing you to not only correctly determine the concept(s) that you need to emphasise in your response to a particular question, but also take less time to do so. You may also need to familiarise yourself with case study material, provided this is required for your exam.
In applying an effective approach that demonstrates an appropriate level of business analytical skills, we can examine the following short answer style question, which targets the Nature of business topic:
"Explain the growth stage of the business life cycle."
Looking at the question, you can quickly identify the key word "Explain", which requires you to relate cause and effect, as well as establish relationships between relevant elements. The question targets the growth stage of the business life cycle. This concept would therefore be the main focus of your answer.
I hope this helps!