Use "copy path" to get the path to the item in the object (then add the msg. part to the begining)
Thereās a great page in the docs that will explain how to use the debug panel to find the right path to any data item.
Pay particular attention to the part about the buttons that appear under your mouse pointer when you over hover a debug message property in the sidebar.
First, did you see @Steve-Mcl's post, marked as the solution to this thread, and have you read and understood it? If that didn't help then please give us more information on exactly what you don't know how to do. Show an example of what you start with and what you want the result to be.
I see that you asked the question again in a new thread. Please don't double post questions. I also notice that you marked as the solution exactly the solution shown earlier in this thread.