(1). B Ltd and W Ltd would form a separate group relief group in addition to the groups already identified. W Ltd would not be in a group with A Ltd because the effective interest of A Ltd in W Ltd would be less than 75% (80% x 90% = 72%).
W Ltd would be in the H Ltd capital gains group (with A Ltd, B Ltd and C Ltd) because B Ltd would have a direct interest in W Ltd of at least 75% and the effective interest of H Ltd in W Ltd would be more than 50% (80% x 80% x 90% = 57.6%).
(2). A Ltd, C Ltd and D Ltd would no longer be in a corporate group. Accordingly, the only group relief group would be A Ltd and B Ltd. This would also be the only capital gains group.