Q.What’s Damaging My Kaempferia & How To Eliminate It
top side leaf – gold colored caterpillar shaped spot, varying lengths. underside leaf – appears to look like a many segmented skeletonized caterpillar living between the top and bottom layers of the leaf.

Certified GKH Gardening Expert
It is hard to say, exactly, which pest that will be. It is definitely larval damage, though. Usually broad spectrum pesticides will be effective enough to prevent further issues.
Here are some articles that will help:
https://www.gardeningknowhow.com/special/organic/what-are-organic-pesticides.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides