You can add the advanced persona characteristics all within the persona's step or under the persona's tab in the Studio panel.
Persona Step:
Once you reach the Persona step in creating your reaction, you'll notice a gearbox icon that refers to the settings of the persona:
Once you click the icon, a pop up window will appear that allows you to edit and add the information:
Note: Regular Expressions are supported for both the Key and Value inputs.
A valid Key and Value must be defined for each characteristics. To match any/all Values, simply use a regular expression ".*" or ".+".
Once completed, click the 'Save & Close' button and click on the option to use the persona:
Persona Tab:
Alternatively, you can create a persona first before you create a reaction in the persona's tab of the panel:
Click on the '+' icon to create a new persona:
The same screen will appear for you to create your persona.
For more, please read this article on how to create a persona.