CyBle_ProcessEvents() process the BLE events generated by BLE stack as soon as you call it.
You can just call it in your main function infinite loop and can make sure that you are not using any blocking functionality ( Blocking Functions) in your application.
There is no direct correlation between these two.
The device wakes up from Sleep at every BLESS event ( Advertisement event or connection event ) and also because of any GPIO interrupt , LP comparator interupt , WDT interrupt etc.
Please refer the below Application Note on Low Power Design for BLE applications.