Hi there,
Yes, you define the pins you want to use, the PIN macro’s do the extra functions. No each MCU have specific syntax to use in order to do it and it’s an all or nothing approach AFAIK.
Post up some specific code or requirement and we can look further suffice to say the original question is answered, if you want a more focused understanding of the methods and uses, check out TRG for the nRF52840 for more. 
HTH
GL 
PJ 