There is often an overlap between what is modeled in ArchiMate and what is modeled in BPMN. How this works is explained in the article about the relationship between ArchiMate and BPMN. A BPMN view creates ArchiMate relationships as soon as the view is made official (note: BlueDolphin only creates relationships, it doesn't automatically delete them). The article about making BPMN work sets official describes how you can make a BPMN view official.
Below is a visualization of the various relationships that are established. These are predefined, and therefore cannot be set differently.