Hi Salvatore,
I don't think you can do it in one filter as you need the count of clicks and count of deliveries received on the same period.
But you can achieve it in an workflow using count on clicks, count on messages received and apply ratio
Other than that, you have 2 ootb filters 'By number of clicks' and 'By number of messages received' that may be helpful
Thanks
David
David Kangni