The Inspector of Scrivener has a column of the bookmark.
Here, we can attach the internal bookmark of the document and the link to external files or websites.
This bookmark is single item-specific. That means it will attach a specific item in Scrivener, including group or text.
Therefore, I can link the project folder itself or the single file.
In the graph below, I put the Scapple file link into the file's bookmark, named “key paper reading.” I can see the preview below the bookmark.
I can also attach the bookmark in the project and manuscript folder.
Furthermore, I can press “Space” on the bookmark to preview the linked file.
Why do that?
We need tons of information and reference outside the Scrivener in academic writing. I permanently save the reference in dropbox and sync in Mendeley. If I move the file into Scrivener, I can not edit it quickly across the devices. Therefore, I prefer to save the links in the bookmark rather than transfer the files into Scrivener. For the example, I linked to Scapple file, and I can edit it separately without opening Scrivener.