I think its Sambucus racemosa plumosa aurea - sometimes lower leaves on this shrubby tree aren't so finely dissected, but just check whether all the less dissected leaves aren't all coming off one branch growing up from the base - if they are, clip that branch out at the base. If you find there's more than one branch with nothing but less dissected leaves on it, clip them all out at the base, but if you find both dissected and not so dissected leaves on the same branch, its fine, don't worry about it.

Many thanks I'm glad we now have a name and thank you for your advice.