I had a question about how to start a question or discussion thread in a particular track. Let's do an example.

Let's say the question is about guided wave radar level measurement technology. Under the Instrumentation group of track, there is Level track. You can either use the quick post widget to start the discussion or question thread:
 

...or go to the Discussions / Questions thread and select new post:
 

If you use the latter approach, you can select either question or discussion, based on the content of your post:
 

If you have other questions, please leave a reply and I'll what I can do to help.