The phrase "nose level" refers to a position or height that is equal to the level of someone's nose. It is used to describe a specific height or point of reference, usually when comparing different objects or measurements. Full definition
They are placing their scents at nose level, so other dogs can smell it, and the wind can spread it, more easily than if the scent were on the ground. (sheppardsoftware.com)
Also, the scent is at about nose level as another dog walks by. (whydoesmydog.com)
The lure should be raised no higher than his standing nose level or he may sit before you can reward the stand position. (perfectpaws.com)