The phrase "different thread" is often used figuratively to mean a different topic, idea, or situation separate from the current one. It implies a shift or diversion from the current conversation or thought. Full definition
This helps eliminate confusion and back and forth that occurs when there are multiple conversations going on at the same time in different threads. (inc.com)
I can handle two different threads of thought at the same time. (religion.blogs.cnn.com)
You didn't wear any clothes made from different threads did you? (religion.blogs.cnn.com)