The drain is too short to the tub by 5/8 in. In other words, you need to raise the drain up closer to the bottom of the tub, I assume.
Fitting-wise, there's nothing that will give you 5/8 " within the area under the tub. Maybe somewhere in all that brown fluff in the wall you could rotate up a 22.5 street el and a regular 22.5 el to get the rise that you need, the bring it back square with other fittings. This is a tough one and will take a lot of trial and error . Might have to get radical with the p-trap. Get a basket full of fittings and go to work on it.