Hey Chao,
Ikebana envisages only one template for the portfolio page, and all pages with that template will display all “project”-type items. One possible workaround is to use portfolio tag archive pages, e.g. this one in the demo. The tag archives are generated automatically and display portfolio items belonging to a particular tag; they have an URL of the form: yourwebsite.com/tag-portfolio/name where “name” is the name of the portfolio tag. You can add portfolio tag archive pages to the menu in “Appearance -> Menus” (in case tags are not shown among the menu insertion options, please click the top-right “Screen Options” tab and choose both “Tags” checkboxes from the list.
Please let me know if this addresses your needs!
Sincerely,
Andrew / Satori Studio