My approach would be a combination of the actual Keywords feature, to flag broader sections of text as containing certain topics, with the Styles feature to do the actual marking of text.
Here is a simple test of the idea:
- Select a phrase of text in the editor, and pop open the Styles panel with Format/Styles/Show Styles Panel (⌃S). You don’t have to actually change colour or anything, the style is going to mainly be cosmetic and we’ll use another feature to do the actual colouring, rather than text formatting. You can if you want to though of course.
- Click the + button to create a new style.
- With the Formatting type set to character attributes only, enable the Highlight Box section and choose a colour.
- Give it a shortcut if you’re going to use it a lot, and then save it.
Okay you’ll see the result in the editor. You could use black here if you wanted to “redact” chunks of text, rainbow colours for topical notes, etc.
Using styles also means you can select and easily copy and paste non-linear chunks of text as well, pulling them into chapters as needed. If you right-click on a style in the panel, you’ll find an option to select all text using that style.
Keywords on the other hand will help you find the selections of text in the first place. I would cut things down as tightly as possible in terms of how much text to keep in each chunk of text in the outliner. The more precise your sections, the better those keywords will be. Since interviews tend to have a little back and forth over one topic before moving on to another larger topic, that cadence might make for a good break point.
Keywords can be easily searched for from the Project/Show Project Keywords panel (⇧⌘K). Select the keyword(s) to search for and click the magnifying glass button (right-click for options).
So the final workflow would be to combine the ability to gather all interview with “Green” text flagged within it, then from the search result sidebar, click the hook arrow button in the sidebar header to put the results into the main editor, view as Scrivenings, and select all green marked text with the style panel.