I think there's some confusion here. Just to be sure, a Dockerfile is not a docker-compose.yml file, they are two different things.
A Dockerfile defines an image while a docker-compose.yml file defines a container, about images and containers.
What Kitematic does is to download an image and let you modify from UI the ENV variables defined in the Dockerfile, check the Dockerfile reference.
If you want to check the Dockerfile of an image from the Kitematic UI:
- Go to the main page
- click on the button with the
... symbol
- click on
VIEW ON DOCKER HUB
- from that page check the latest Dockerfile.
Kitematic has a caching\config folder in (Windows):
C:\Users\<YourUsername>\AppData\Roaming\Kitematic
But they are just binary files used for caching downloaded images, there's no configuration there (at least in clear text) and for sure no docker-compose.yml files.