Issue:
You have multiple schemes (targets) to be released, but you are not sure how to release all the targets in a single build.
Possible solutions:
Although currently there is no way to release all the schemes in one build, you can separate these build configurations into different Workflows and use Workflow chaining.
This way you can run your builds for technically all of the schemes with one trigger, start the first one on commit and use that to trigger the other Workflows.