whether i can use "include" only for .gitlab-ci.yml ?

I would like to understand whether include is only for .gitlab-ci.yaml ? I have multiple java projects and I am using include with .gitlab-ci.yml, similarly I want to use the "include" for some of my application.yml or application-custom.yml which needs to be shared for multiple repositories, is that possible? I have tried the same way, but when I am building the jar it doesn't parses the actual content, instead it takes as include https://gitlab.com/api/v4/projects/xxxxxxxx/repository/files/application-custom.yml/raw?ref=master&private_token=sdssnsssxxxxxxmmm.yaml" how can I parse the actual file, something like yamllint once cloned and before build?