I’m scratching my head trying to work out how to enter a box set which packages six albums on four CDs, so the underlying Release Groups are spread across the individual mediums.
Here is a partial listing: Three Ragas - 1956
1-1 –Ravi Shankar Raga Jog 28:12
1-2 –Ravi Shankar Raga Ahir Bhairav 15:29
1-3 –Ravi Shankar Raga Simhendra Madhyamam 10:51 India’s Master Musician - 1958
1-4 –Ravi Shankar Raga Puriya Dhanashri 11:24
1-5 –Ravi Shankar Raga Charu Keshi 13:36
2-1 –Ravi Shankar Kafi Holi (Spring Festival Of Colours) 7:13
2-2 –Ravi Shankar Dhun (Folk Airs) 5:51
2-3 –Ravi Shankar Mishra Piloo (In Thumbri Style)
I would simply create a new release group. I would do that anyway even if the discs did correspond 1:1. You can link the original release groups and the box set release group with this relationship.
Yes, such linkages are currently not represented at the medium level.
However, they are represented at the release-group level and at the recording level.