Is it possible that in the property spring.liquibase.change-log i point to a changelog file outside of my jar file?
Yes you can point to a changelog file outside of the jar file using a relative path or add ‘/’ to the classpath parameter. You can find more details on this page
If you are using the Java liquibase Api just use a ResourceAccessor
ResourceAccessor accessor= new FileSystemResourceAccessor("C:\\Users\\demo\\Documents\\Migrations"); return new Liquibase(changelog, accessor, connection);