This is not possible using the device's fingerprint sensor. By design, to prevent apps from obtaining the user's fingerprint data, there is no API that allows an app to access fingerprint data. There is also no API that allows different fingerprints to be distinguished, as they are all considered to be from the device user that is running the app.
If you need to save and compare fingerprints in an Android app, your only option would be to separately obtain an external fingerprint sensor that connects to the Android device, and use its SDK to read and store fingerprint data.