Understanding of current things in variety (7)
I believe the answer is:
Here is my best explanation:
'understanding' is the definition.
(insight is a kind of understanding)
'current things in variety' is the subsidiary indication.
'current' becomes 'i' (symbol for electric current).
'in variety' indicates an anagram (I've seen this in other clues).
'things' with letters rearranged gives 'nsight'.
'of' is the link.
(Other definitions for insight that I've seen before include "Deep understanding", "The ability to perceive the true nature of something", "Intuitive understanding", "Acute understanding", "Understanding", "Perceptiveness", "Intuition", "Things I have understanding of", "Special knowledge" and "Deep perception of a situation".)