OK, so this will be easy. Hopefully once you do it you will do one of those Homer Simpson "D'oh" exclamations.
Just make a second relationship and when it offers to make a new field for you instead select the field that you already have from the first relationship for the Manager ID. Then look up what you want including perhaps the Manager ID from the Manger! So like the 2nd Level Manager ID and then repeat another relationship using [Second Level Manager ID] as the reference field on the right side of the relationship. Just make real sure that you name all these fields properly so you don't confuse yourself.