Note this from Implementation Guide, Chapter 3: Creating and Editing Global and Product Parmlib Members:
"How To Set Up a Data Sharing Environment”
By defining all subsystems in a data sharing environment to each SETUP member, you can ensure that the products will be able to properly process DB2 subsystems that are part of data sharing groups. You can also specify the group attachment name.
To set up a data sharing environment, define each subsystem ID that is a member of the data sharing group in the parmlib member SETUPxx. Each member's CATALIAS parameter will be the same and correspond to the group's CATALIAS. The BSDS will be unique for each member SSID."
For shared subsystem all the group SSID must be present in SETUP00 member.
If not all then at-least those SSID which can be access from specific LPAR.
Please DEFINE all SSID of the data sharing system in SETUP00 member of CDBAPARM library.