"taxpayer is the sole member of one partnership"

Not a partnership, then. There is no partner to the one person. That means "disregarded entity."

"and then that partnership"

Are you confusing LLC (a State organizational construct) with "partnership?" Right here, you still have "an individual"...

"is the Managing Partner of another partnership"

Is this person, your only person under discussion so far, the only "member/partner" here, as well?

So far, you have reviewed one person.