how to use 对此 in a sentence? What do you think should be done about it?
你觉得对此该做什么？

this is the translation online I found for this English sentence. The translation makes some sense, but I'm not quite sure what the point of "对此" is. I know it means "towards this" but I don't know why it's used here.
What 什么
you 你
think 觉得
should 该
done 做
about 对
it 此  

So, 对此 is used because of "about it".