Allow to retrieve a given button added to a group

[Escain]

1. Create a QTopMenu with a tab and a group.
2. Insert a button at position 0 (button A)
3. Insert a button at position 0 (button B)

How to remove button A? the component adding A, might not know about B, thus, removing the button at 0 is removing the wrong button.

A better mechanism to retrieve a given button must exists.