Assistance setting up multi-value variables from url

Perhaps I am approaching it wrong, but I am trying to pass a multi-value variable to grafana via url.
I then want to use that variable to repeat rows of info about some systems, primarily gauges.

I created a custom variable, which requires me to provide the values ahead of time.
If I set the value(s) in the url, it shows the gauge of the first system (although it lists all of them provided as system1+system2+systemx). However if I try to do ‘select all’ from the dropdown for the variable, that resets the system names to whatever my default values are.

Is there a way to go about this?

Brian Andrus