Hi Matias,
You want basically Grp1 to Read the record of Grp2 and Grp 2 to read the record of Grp 1.
That raises a question - why they need to be in a different BU if both can read each other records?
If it is just to restrict write privilege then that can be achieved using Two teams under one BU.
So you can have Grp 0 as parent BU and Grp 'X' as child BU. Inside Grp X you can have two teams - Grp 1 and Grp 2.
Grp 1 and 2 will have role BU level Read and user-level RW. The cases can then be owned by teams.
But if you still need 3 BU - then you can have Grp 0 as a parent and Grp 1 and Grp 2 as a child. Grp 0 users will have Parent BU access so they will get access to 1 and 2.
Grp 1 and 2 users will have just BU level R/W access so they cannot read each other records.
You can then create a team in Grp 1 called 'Grp team 2' and add all users of Grp 2 under this team and give the team BU level Read.
Similarly, create a team in Grp 2 called 'Grp team 1' and add all users of Grp 1 under this team and give the team BU level Read.
Thanks,
Prateek
