The following lines show how to attach the Pufferfish Song audio file to the Novice instance of the Pufferfish DITA map and attach the Pufferfish Circles image file to the Expert instance of the same DITA map:
<?xml version='1.0' encoding='utf-8'?>
<controlFile>
<resources>
<resource>
<filePath>_pufferfish.ditamap</filePath>
<instances>
<instance>
<filePath>Novice.ditaval</filePath>
<attachments>
<attachment>
<originId>pufferfish-video</originId>
<displayName>Pufferfish Video</displayName>
<filePath>pufferfish-video.mp4</filePath>
</attachment>
</attachments>
</instance>
<instance>
<filePath>Expert.ditaval</filePath>
<attachments>
<attachment>
<originId>Circles</originId>
<displayName>Pufferfish Circles</displayName>
<filePath>pufferfish-circles.jpg</filePath>
</attachment>
</attachments>
</instance>
</instances>
</resource>
</resources>
</controlFile>