Can a level shifting circuit shift voltage the other way around?
Does the level shifting circuit get the 5V and shift it back to 3.3V?


Yes, that circuit works bidirectionally although it might be a good idea to have a pull-down resistor on the 3.3V logic line to 0 volts (see later on counter argument).

When the 5V side is at 5V, R1 pulls up the 3V3 side via the base-emitter junction (a forward biased diode). When the 5V side is at 0V, the base-collector region becomes forward biased and this pulls the base down to approximately 0.7 volts and the emitter (with the pull-down resistor mentioned) would fall to 0 volts.

However, you could make a case for the transistor working (albeit with reduced beta) in an upside-down mode (i.e. collector and emitter swap places). This would naturally tend towards thinking about a pull-up on the 3V3 line. I'd rather use a MOSFET version: -



It's a little more clear cut on how the 5V side drags the 3V3 side down to 0V - it uses the body diode in the MOSFET to achieve this and therefore doesn't need a pull-down on the 3V3 side.