How to use Template Variables in other Templates

I just want to use defined Template Variables in other Templates.

I want to build one dashboard with two templates. The available options on the second template should depend on the user choose from the first template.

Example : First Template CONTINENTS (America, Africa, Europe, Asia)
If the user choose Europa then :
Second Template COUNTRY (Germany, Italy, Spain, Poland, and so on)

I see that the PREVIEW works already, but the “select option window” for the Second Template COUNTRY is blank.

----- In Detail ----- for an InfluxDB ------ in one dashboard ----

Template 1: 
name = serie
query = show measurements

Template 2:
name = cluster
query = show tag values from $serie with key in ("cluster")

Now it works, it was only a display problem in the browser windows.
After switching to another topic and switching back to this dashboard it works - great :wink:
I’m happy !