I think you’re confusing the concepts of templates and devices.
I’m guessing that you mean you want to have one dashboard which displays the data from several devices?
If so, this isn’t how Blynk IoT is designed to be used. However, there are some workarounds. Automations can be used to send data from one device to another, but there are restrictions that mean this may not be suitable for your use-case.
Otherwise, data can be sent from one device to another using the REST API or Node-Red. More info here…
Different equipment on the same screen - #13 by PeteKnight
If this isn’t what you meant then you need to clarify your question.
Pete.