I think this was an option in older Premiere versions- to basically right click on a single element in the timeline and export that one thing as a piece of media. Take a sound file, right click, export as an MP3, for example. Basically have granular control over exporting media and not the whole timeline. It may have also been simply located in the File drop down. File->Export selection or something to that effect.
Double click the single element to get it into the source monitor then 'export media' this will open the normal export dialogue but with the source monitor material.