Copy the event.
Note: Copy the full event, not only the condition or action. Fusion refuses to paste single condition/action to text.
Paste it as text (e.g. paste in notepad).
Copy the text that you want to search (e.g. Test of Active, "Test" is the alterable value name).
Use "Find All" to search in fusion.
By this method you can search almost every condition/action of any extension in fusion.