A process map object is an internal M-Files multi-file format and therefore it cannot be transferred to another vault simply by copy & paste. However, process maps can be easily exported or imported and replicated using the standard M-Files tools (see Content Replication and Archiving).
If you want to manually copy a process map or transfer it to another vault, simply copy the XML content in the object. The PMAP.XML file contains the entire drawing in XML format. This is the only information that needs to be transferred:
You have now successfully migrated the object and can continue using the map as usual. However, please note that commands to non-existent objects may not work in another vault. Also, properties that are not accessible will show up as #NA#.