Currently with a Samsung Galaxy S8, but I believe this is common to other devices, I can setup fingerprint unlock which requires a password when the device starts up or if I fail to scan my finger correctly a few times.
I would like to add another limitation: allow fingerprint unlock but require a password unlock every x minutes/hours or some other configurable time limit.
A somewhat silly scenario to illustrate the need: suppose I fall asleep on the train, I don't want anyone to be able to scan my finger and unlock my phone. I still want the comfort of unlocking the phone with my finger while knowing that after a while it will lock itself and require a password.
Is there a setting I'm missing or an app that can do that?
Following @beeshyams's answer, here are my current settings.