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 wordplay.
'current' becomes 'i' (symbol for electric current).
'in variety' indicates anagramming the letters (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 "Visible", "Enlightenment", "apprehension", "Special knowledge", "The ability to perceive the true nature of something", "Clear understanding", "Intuitive understanding", "Clear or deep perception of a situation", "Ability to understand" and "Perspicacity".)