Beetles are present during elderberry flowering, where they eat pollen and leaves, and then lay their eggs on leaves or canes near the ground. To control this pest, prune out infested elderberry canes. Borer insects can cause stems to die as well. These are the most common issues on elderberry. Game birds, squirrels and other rodents, and several kinds of browsers also feed on the fruit or foliage of elderberry. Bears love to eat the elderberry fruits while deer, elk, and moose browse on the stems and foliage.

I have seen no bugs or eggs on the leaves but will look more closely this summer. Attaching a closer look at the damage. Photo taken in late October after some new leaves had emerged as they do every year.

Nope, it's not critter damage. :)

Thank you!