Neither PATRAN nor I-deas understands Ansys Polyflow’s concept of subdomains. The subdomain information is converted from the material property ID, which is an element property. If you want to generate more than one subdomain, you should select appropriate elements and change their material property ID. For subdomain 2, for example, change the material property ID to 2. This is done through the PMAT directive in PATRAN, and through modification of the material ID property in I-deas. The subdomain numbering will be reported by Ansys Polydata after the conversion is complete.