Configuring custom rules decides what happens with the executable files of the processes that aren't currently installed in the endpoints. This provides the sysadmin with scope to define the rules based on the application resources that can be derived from their properties or via executing a command in the CLI.
Custom Rules in Windows have the following rule types:
To fetch Product Name and Executable Name, right click the application (the original executable, not the shortcut) and select properties (alternatively, selecting the application and pressing Alt+Enter also displays the properties).
In this application properties, the Product Name is the same as titled in the pop-up, while the Executable Name is the one besides the Original filename. (Eg. Firefox executable name will be firefox.exe)
To know the Vendor Name, click on the tab Digital Signatures in the application properties. The value under the column Name of Signer is the Vendor Name.
Finally, to know the File Hash value, execute the following command in the command prompt,
certutil -hashfile "path_of_the_.exe_file" SHA256
(Note: In the file path, include the .exe file as well)

For Windows Powershell, execute the following command,
Get -FileHash "path_of_the_.exe_file" -Algorithm SHA256Custom Rules in Mac have the following rule types:
To fetch the application properties, follow the steps below:
codesign -dvvv "path_of_the_.app_file"
Example: codesign -dvvv "/Application/Google Chrome.app"
(Note: In the file path, include the .app file as well)
In this case, the Application Name is Google Chrome, for which,
Note: If the Team Identifier is specified as "not set" and it contains the Platform Identifier, then the Team Identifier should be provided as "APPLE" (case-sensitive).

codesign -a x86_64 -dvvv "path_of_the_.app_file"
codesign -a arm64 -dvvv "path_of_the_.app_file"
Note: Entering SHA-256 value as File Hash for an application that is signed will not be processed as a valid custom rule.
codesign -d --extract-certificates "path_of_the_.app_file"

ls -l ./codesign*
If successful, check if it is signed by entering the following command,
security verify-cert -c ./codesign0
The result certificate verification successful indicates that Google Chrome is signed. So, it is recommended to use CD HASH value.
If an application is unsigned, the command codesign -d --extract-certificates "path_of_the_.app_file" displays result like this.
For this application, which is not signed, enter the following command to know the SHA-256 value,
shasum -a 256 "path_of_the_.app_file"
The resultant SHA-256 value can be entered in the File Hash field.