Conditional output works in the same way on all the levels where it is supported: You mark a part of your project (text, graphic, topic, chapter etc.) with a condition, referred to as an "include option" or "build option", and then choose whether you want to apply the condition when you publish your project.
You can search and replace conditional text tags. Just select "Conditional Texts" in the "Find where:" field when you search. See Searching for details.
Variables and Conditional Output (Reference)