The option of dynamic attachments is available within template emails and custom defined emails. Please note that PDF file generated within a process can only be send as an attachment in emails defined within the process generating the PDF files. Public mail templates can't use them.
Name: Here you can define the filename of the attachment. It is possible to use placeholder like #REPLACE-FORMFIELD-Lastname# for example. You need to define the file extension manually.
Document location: Set here a reference (URL or local path) to were SSP can find the attachment. Please note that the reference should be accessible for the server. If you want to include a generated PDF file, use the dropdown list and select Process. Under process you'll find the PDF file defined or a generic option to include the default PDF report.