A Globally reusable workflows is a workflow that can be associated to any list, library, or content type in a site collection. In contrast, reusable workflows are localized to the site.
Symptoms
You are migrating a source list, library, or content type with a globally reusable workflow, but the globally reusable workflow does not appear in the destination.
Details
Globally reusable workflows are currently not supported for migration because they are not managed the same way as reusable workflows.
Solution
You must recreate your workflow at the destination after migrating.