DRV8323R: Where is the return path for low side gate drive current? GND or current sense input (SPA, SPB, SPC)

The high side driver seems to have a pin specifically for return current, but it is not entirely clear how the return current path is on the low side? And on the variants with no current sense amplifiers, are the SLA, SLB and SLC pins then connected to pull down transistor on low side gate driver? Or is ground used for return current? 

Thanks!