The profile has no documentation and it is impossible to document something that no one has documentation for that is known.
I am quite sure they are related but not necessarily father and son.
There are quite a few of the same name so hard to know who is who.
The best I have found for relationships for Murdoch other than his son is he possibly had a brother George who died before 1522
Protocol book of Gavin Ros 1512-1532
#557 13 May 1522 mentions late George Nesbyte
#1008 Instrument narrating that Mariota Nisbitt, daughter of the late George Nisbitt, burgess of Air, obliged herself to relieve Murdac Nesbitt, her uncle, of all things contained and specified in an act made in the books of the court of the official of Glasgow between her and Murdac and John Kennedy, which contents Murdac promised in the name of Mariota at Air 1 June 1529 Witness William Nisbet (95a)-
There is no mention here either see
https://en.wikipedia.org/wiki/Murdoch Nisbet