I might need to revise the manner in which I've worded these instructions.
- In the zip you downloaded, there is this file: Motion Pictures.xml
- Open it and in the first few lines, you will see the formulae shown in that linked screenshot.
- Copy each of the formulae to whichever virtual tag number they correspond with in MusicBee.
So after opening the virtual tag panel in Preferences -> Tags(1) -> under custom tags -> Define New Tags...
Scroll down to virtual tag #24 and paste this code in there:
$Upper(<.Ext>), <Sample Rate>, <Bitrate>, <Channels>, <Time>
Repeat this step for the other virtual tags as well.
Once these are set up, you'll see various figures being displayed in different views inside the Theater Mode (figures like the total number of tracks by an artist, etc.)