I don’t know of any way to watch the behavior of NVLINK with the profilers. They capture their data, presumably for an entire application run, then you get to view or inspect it.
The nvidia-smi tool or the underlying NVML library could be used in such a way to get periodic updates on NVLINK traffic. I think scripting to do this with nvidia-smi should be fairly obvious, however I wouldn’t be able to put together a script for you. If you decided to do it with NVML library, then you would need to create a program to do that. I don’t have any suggestions about getting started there, other than the NVML SDK, which includes example codes.