VishnuMundhra You can toggle on the’flip to silence’ toggle in advanced settings of the dialer app to silence an incoming call
OR
Press & release the volume button.
Touch the bell & then the vibration icon on top of the volume slider to turn them both off.
I’m afraid there’s no single touch solution yet like the silent switch on oneplus phones.
Maybe N may add a button press mapping or a gesture control for this purpose in the future.