Config Server is pretty flexible, but I don't think you can change the pattern to an arbitrary value. My understanding is that you can use the following patterns (for a Git backend):
/{application}/{profile}[/{label}]
/{application}-{profile}.yml
/{label}/{application}-{profile}.yml
/{application}-{profile}.properties
/{label}/{application}-{profile}.properties
https://cloud.spring.io/spring-cloud-static/spring-cloud-config/2.1.4.RELEASE/single/spring-cloud-config.html#_quick_start