I'm not exactly certain what you are asking here. You can add multiple data sources to PowerApps. I'm not certain what this has to do with graphics. I have some additional information on data sources below; if you would like to take a look and try to learn more.
Sorry if I wasn't clear, I've a graphic that i created in my power apps, it's a line graph and this one takes data from my data source, "Teachers" in the property "Item". My question is how can I add other data source in my line graph.
I've my datasource "Teachers" and it's in my line graph, and I've other datasource that is "Grade" and i wanna add it in that line graph.
Could be possible? I was searching that it's not possible just only with power BI.