I have and Ecobee thermostat with multiple sensors. I like to look at the temperature charts when I click on the temperature sensor on the home assistant front-end. I would like to be able to combine these different sensors onto one trend chart that is in its own card (like a group) on the Home view. This would make it easier to correlate what the different temperature readings were in the different locations a the same time. I envision that this Trend Chart component would be configured just like a group and simply contain a list of the sensors that you would like displayed. It would also be good if it could handle sensors of different units of measure so we could display temperatures and the humidity on the same chart as well.
A more advanced version of the Trend Chart would allow you to set the time duration displayed and to zoom and pan around the chart. But if we could just get them on the same chart to begin with that would be a great first step.
This is way above my current skill set of programming, but I think that it would be an extremely useful component if the community was able to pull it off.