@Marktiger0205 Thank you!
Framework datacard [Update] to be: Dropdown3_1.Selected.Result
For Control no, I got same example here. The detail info appears when you click your Dropdown2_1.
Now take a look at [value] being shown, please try to change [Update] property of Control no. like this:
Dropdown2_1.Selected.Control_x0020_No_x002e_

ps: you might need to input value yourself 🙂
Hope it helps your problem,