Hello,
Apologies for the misunderstanding!
What you can do is position the Page Content module under the Portfolio section and add a button with the link to all projects within its content – https://share.getcloudapp.com/xQujkpgA.
On the other hand, I can see you’re already using the page content module before the footer. Other than the above workaround, maybe you can make use of the Image Menu/Icon Menu module. However, the layout will not look like a button – https://share.getcloudapp.com/6quvAW2n.
Hope this helps and let us know if we can assist you further.
Kind Regards,
Karla