Opus lets you change many things to do with how it displays the contents of folders - view mode (details, thumbnails, etc), columns displayed in details mode, the sort order, grouping options, and more. Collectively these settings are referred to as the folder format.

You can save the folder format for specific folders so that those folders are always displayed in a particular way.

The Folders / Folder Formats page in Preferences is the main interface for configuring saved folder formats. You can configure several different types of folder formats through that interface:

More:
Folder Formats
Content Types
File Type Groups