This will open the selected format in that format's default viewer for a specific book.
- Copy the book's calibre: protocol format link to the clipboard from the Book Details panel (right click white space), viz:

You can use a keyboard shortcut of you prefer, placeholders are in Preferences->Shortcuts->Edit Metadata
- Create a new shortcut via desktop right click, select New->Shortcut
Paste the clipboard into the new shortcut popup

- Click Next and type a name

- Click Finish
You can paste the calibre://view-book link into any app that can handle urls, e.g. a note taking app. Even another book in another calibre library.
BR