Extract lambda parameter
The Extract Lambda Parameter refactoring helps you extract an expression or statement into a new parameter with a lambda expression passed as a corresponding argument. For example, this could be a comparator passed to a sorting function.
The following demo illustrates the usage of the Extract Lambda Parameter refactoring, as well as Extract Function, Extract Parameter, and Live Templates:
Extract a lambda parameter
Select a code fragment that you want to extract into a lambda parameter.
Call from the main menu or select Lambda Parameter from the Refactor This (Ctrl+Alt+Shift+T) popup.

In the dialog that opens, specify the name, return type, and declaration placement for the new lambda parameter:

Review the changes in the Signature Preview field and click Extract when ready.