Assume you have a domain 'sales' as defined by release config sales.yaml provided as shown in this example here.
In order to build the artifact of the packages defined by the above release config, you would use the the build command with the flags as described here.
If you require only to build packages that's changed form the last published packages, you would add an additional diffcheck flag.
diffcheck will work accurately only if the build command is able to access the latest tag in the repository. In certain CI system if the command is operated on a repository where only the head commit is checked out, diffchek will result in building all the artifacts for all packages within the domain