How to use the sub-grouping header

[The Incredible Boom Boom]

And I'd also love to know where I can actually learn how to use the script language so I can figure these things out myself in the future.

Have you happened across the MusicBee Functions page?

Edit: 5 minutes after I posted this, I figured out a solution for me.
I'm using

Code

$If(<Disc Count>>1,$IsNull(<Disc#>,Null,"• Disc "<Disc#>)" "$IsNull(<Original Album>,," ~ "<Original Album>),)

right now and I just define the <Original Album> as whatever the CD is called and the normal album is defined as the name of the compilation.

I'm sure there's a more elegant solution tho.

Good job working it out. Looks good other than you don't need the "Null" in your first $IsNull() function.