Text Pattern Filter is designed to tell system what pattern of text user want to find for replace.
User need to fill the pattern follow rule of Syntax of Search Pattern.
Note: Don't worry if you don't know Syntax of Search Pattern, there are a lot of examples to tell you how to do, and the easiest way is just filling fixed text here such as 'abc'.
By right clicking mouse, user can select available Macros or Symbols.
How does system match a text by pattern:
If Replace Unit is "Para", system will find any paragraph matching defined pattern, and replace it with new text.