Thank you for your message.
With the libraries in PRTG, you have the possibility to move the devices you desire in a library node on the left. Then if you desire to only display specific sensors from that devices based on their tag, you can use the options Show a collection of filtered sensors and Show only sensors with specific tags.
You can also add the sensors you desire on a library node next to your devices instead of filtering their sensors. To do so, simply create a new node and use the same options mentioned above.
If you have questions, let us know.