How to find a substring from an existing string?

In order to find a substring from an existing string we make use of substring function available in HuLoop.

Select SET command from the action dropdown and provide a variable name in Element key where output will be stored, edit parameter section and click on Form, select functions from the dropdown and select SUBSTRING function and provide the values in the form.

First parameter: main string.
Second parameter: start index.
Third parameter: end index.

Output for the above step will be Test which will get stored in z variable.