can this adapter plug into a thunderbolt port off a thunderbolt external drive. The drive would be connected to the computer through thunderbolt

No, the Mini DisplayPort male connector will not work (i.e. will not plug into a thunderbolt-2 port with the objective of using this adapter - a Mini DisplayPort to DVI Adapter - to transfer data to and from this storage drive).
On a personal note: I sure wish Apple would design and manufacture a [Thunderbolt-2]-to-[USB-C / Thunderbolt-3] adapter. I have no knowledge at all, considering the differences in wiring between these two fantastic data-transfer-interfaces, if such a connection would even be feasible. Perhaps someone familiar with this aspect of electrical engineering can shed some light on this issue.
I hope my answer was helpful to you.

• Answered by Nestor L M from Atlanta
• Mar. 15, 2019
• Flag as inappropriate Answer 1