Reward users if their referrals make more referrals

Hi what i mean is for example

user 1 - referred - user 2 - and user 2 - referred - user 3

then user 1 win points for the user 2 and more points because his referred (user 2) referred user 3

is like raward an user if his referrals make more referrals...

i tried to do this with rules, but i did not find the way of fetch the parent referring user... I only can take (after a new referral is recorded) the first levl referring user, in this case i only can give points to the user 2, but how can i give also points to the user that referred user 2 (in this case user 1) ?

any idea?
hope some help. Thanks