A Little help with Parameter List?

Hey All.

Using FTV .ME V8.1
I have several parameter list set up in the "display settings" field for many display goto buttons.
I have used parameter files with global objects that looked something like
{[topic]VFD1234} and in the global object definition would be links to the tags within VFD1234.

But now I am looking at the following. {[#1.tagname.subtagname}.{#1}.

I have been reading about this but I do not see in the global connections tab, or in the parameters file tab where there are any expressions configured. Or how a connection is made to the PLC with this {[#1.tagname.subtagname}.{#1}.

Any advice is appreciated.

Thanks

Ok,
So, I have figured out with much head thumping, That the original display gets called with an associated parameter file.
In the pics shown this connection would be with "{[PLC]Blender1},{Dummy_1}"
Then, any displays that are called within the display are associated with the parameter file of the original display with something like {#1.Active}.
I have never seen this done so it has certainly taken me some time to figure this out.

My only question is now, how would "{Dummy_1}" be used.

Now I just have to figure out how to build on what is here.
What a head spin!!

Thanks