I can't think of any with round leaves, let alone double leaves. I'm also struggling to see how a saucer-shaped leaf could be described as small, but maybe it's me!

If I were you, I would contact the British Clematis Society. Someone there should be able to help.

Its not a large sauce leaf small and round thanks might check them out

the only clematis I can think of with different leaves which are not entirely round, but relatively, is Clematis texensis, scarlet leather vine, but this business of 'another leaf on top' doesn't fit with that.

Eek! I've just bought a texensis (Princess Diana) and the leaves are not even remotely round, so I hope it hasn't been wrongly labelled!

Not all texensis varieties have those sort of leaves, Roseirose, its the one known as 'scarlet leathervine' which does.

There's a honeysuckle with perfoliate leaves, Lonicera caprifolium, which has leaves a bit like this description. Can't think of any Clematis though.

Thankyou my mistake yes it is a honeysuckle.