Canadian NEXUS reciprocity with other countries trusted traveler programs?
 

The US Global entry program seems to have reciprocity with the trusted traveler programs of other countries. That does not seem to be the case with Nexus (unless you count USA global entry program in that category!).

Has the nexus program any relationship (even Mexico's) with other countries' trusted traveler programs?

Nexus is a requirement for Canadians to get an APEC business travel card:

https://www.cbsa-asfc.gc.ca/prog/abt.../menu-eng.html

But you still have to apply for it, you can't use your Nexus card.

You don't get visa-free travel, but get to use their special lanes.

This is not first-hand information, just something I found while doing similar research.