Are you defining both the Roon Work and Roon Part tags?
Here’s what a couple of track’s meta data look like for one of my box sets:
File = /Users/craigpalmer/Desktop/Fare Thee Well Test Album/1-01 Solder Field, Chicago, 7-3-15-Box of Rain.aiff
Title: Box of Rain
Artist: Grateful Dead
Album Artist: Grateful Dead
Album: Fare Thee Well Test Album
Track: 1
Disc: 1
Year: 2015
Genre: Pop & Rock
ISRC: USRH11501778
Roon Work: Soldier Field, Chicago, 7/3/15
Roon Part: Box of Rain
File = /Users/craigpalmer/Desktop/Fare Thee Well Test Album/2-01 Solder Field, Chicago, 7-3-15-Mason’s Children.aiff
Title: Mason’s Children
Artist: Grateful Dead
Album Artist: Grateful Dead
Album: Fare Thee Well Test Album
Track: 1
Disc: 2
Year: 2015
Genre: Pop & Rock
ISRC: USRH11501785
Roon Work: Soldier Field, Chicago, 7/3/15
Roon Part: Mason’s Children
It’s the last two fields that create the organization your trying to get…
If you have your data in Yate, click on “View → Metadata as Text” and take a look and see what happening with yours.