how will unemployment be automatically corrected by market forces?

Unemployment is automatically corrected by market forces i.e, aggregate demand and aggregate supply. This concept is already covered in our study material. Follow the given link and scroll down to the topic 'When aggregate demand exceeds aggregate supply' and 'when aggregate supply exceeds aggregate demand' to view the same.
 
https://www.meritnation.com/cbse/class12-commerce/studymaterial/economics/introductory-macroeconomics/income-determination/341_1989_5845#slide1_Adjustment Mechanism