@devonkelley
You could put both the NDA and the second document in a single DocuSign “envelope,” then configure sequential signing so that:
Signer 1 signs the NDA first.
Once Signer 1 finishes, Signer 2 (who could be the same person or a different person) gets access to sign/review the second document.
This ensures the second document becomes available only after the NDA is signed. However, all documents are technically visible to signers in the same envelope (though the second document may be “read-only” until it’s their turn). It’s not a 100% “unlock” but it’s close to a gating process within a single workflow.