There is no group transient key, no group KCK, and no group KEK.
Pairwise Transient Key (PTK) is partitioned into KCK, KEK, and temporal key. Group Temporal Key (GTK) is not partitioned. It is a temporal key.
KCK and KEK taken from the PTK are used in both the 4-Way Handshake and the Group Key Handshake.
I hope this helps. Thanks. /criss