Stock screening is a complicated topic. Beyond usual attributes, many derived (for example, P/CF is a derived attribute of a given stock) ratios or attributes can make this convoluted for beginners. And then, there are "machine learning" models learning to pick awesome stocks based on data, especially through backtesting with historical data streams.

For Indian stock market, I use the screener.in tool (free) to save my screens. You can play with some public screens listed over there.

Here I present a specific screen focusing on "Undervalued Mid-Cap and Small-Cap" companies.

Free cash flow > 0 and  
Debt to equity < 1 and  
Pledged percentage < 10 and  
Current ratio > 1.4 and  
EPS > EPS last year   and  
Sales growth 3Years > 10 and  
Profit growth 3Years > 10 and  
Profit growth > 10 and  
Sales growth > 10 and  
Average return on equity 3Years  > 20 and  
Return on equity > 20 and  
Average return on capital employed 3Years > 20 and  
Market Capitalization < 10000 and  
Market Capitalization > 50 and  
Profit growth 3Years > Price to Earning  and  
EVEBITDA <= 10 and  
Volume > 1000  

Running this across all Indian stocks results just 3 stocks

Feel free to play with screening criterions and research meticulously resulting companies (manual research is tremendously important for any good analyst / investor)