The Pricing Procedure contains a lot of complexity within it. But to get an immediate view on what is happening within the Price Procedure and to check the logic being executed take a look at the Pricing API Execution log.
Turn On Price Logs Capture in Salesforce Pricing Setup
Go to the Pricing Operations App
Select the Pricing Execution you want to inspect from the list
Click through to the Debug Details
The Price Waterfall execution is then shown element by element
So you can inspect filter rules and data used with outcomes, input price, element variables, and output of the element.