db2 z/os foreign keys column extraction is not joining the catalog tables correctly and extracting extra columns from other foreign keys when the key names where of the same name.
The following create statements will give you the objects which would cause the tree node and extraction to pick up the column data for the foreign keys.
CREATE TABLE "NORTHWIND"."A" (A INTEGER NOT NULL, B INTEGER NOT NULL, C INTEGER NOT NULL, D INTEGER NOT NULL, E INTEGER NOT NULL, F INTEGER NOT NULL, G VARCHAR(25))
GO
CREATE TABLE "NORTHWIND"."AA" (A INTEGER NOT NULL, B INTEGER NOT NULL, C INTEGER NOT NULL, D INTEGER NOT NULL, E INTEGER NOT NULL, F INTEGER NOT NULL, G VARCHAR(25))
GO
CREATE TABLE "NORTHWIND"."AB" (A INTEGER NOT NULL, B INTEGER NOT NULL, C INTEGER NOT NULL, D INTEGER NOT NULL, E INTEGER NOT NULL, F INTEGER NOT NULL, G VARCHAR(25))
GO
CREATE TABLE "NORTHWIND"."B" (A INTEGER NOT NULL, B INTEGER NOT NULL, C INTEGER NOT NULL, D INTEGER NOT NULL, E INTEGER NOT NULL, F INTEGER NOT NULL, G VARCHAR(25))
GO
ALTER TABLE "NORTHWIND"."AA" ADD CONSTRAINT "pkey" PRIMARY KEY ("B", "C")
GO
ALTER TABLE "NORTHWIND"."AB" ADD CONSTRAINT "pkey" PRIMARY KEY ("C", "D", "E", "F")
GO
ALTER TABLE "NORTHWIND"."A" ADD CONSTRAINT "fkey" FOREIGN KEY("B", "C") REFERENCES "NORTHWIND"."AA" ("B","C")
GO
ALTER TABLE "NORTHWIND"."A" ADD CONSTRAINT "fkey1" FOREIGN KEY("C", "D", "E", "F") REFERENCES "NORTHWIND"."AB" ("C", "D", "E", "F")
GO
ALTER TABLE "NORTHWIND"."B" ADD CONSTRAINT "fkey" FOREIGN KEY("C", "D", "E", "F") REFERENCES "NORTHWIND"."AB" ("C", "D", "E", "F")
GO
ALTER TABLE "NORTHWIND"."B" ADD CONSTRAINT "fkey1" FOREIGN KEY("B", "C") REFERENCES "NORTHWIND"."AA" ("B","C")
extraction for tree node and object details both changes to fix the issue.