There is not a way to use the focus keyword as part of the breadcrumb pathway, automatically. We have a feature request open here: https://github.com/Yoast/wordpress-seo/issues/7940 to do just that. We suggest commenting on it so you may be kept aware of updates. You may need an account in order to comment.
In the meantime, the only workaround would be to manually add in the preferred Breadcrumb title by going to the Yoast SEO Metabox->Advanced (the gear icon)->Breadcrumb Title. See: https://pasteboard.co/GMCFVMH.png