In the code, between each run of PDFActiveSheet, you neeed to change the value of the dropdown cell.
Let's say that cell is B2:
Sheets("the name of the sheet that cell B2 is on here").range("B2").value = "something"
Application.Run "'Copy of North TSC Format (2).xlsm'!PDFActiveSheet"
Sheets("Talent Scorecard - CV Passenger").Select
Sheets("the name of the sheet that cell B2 is on here").range("B2").value = "something else"
Application.Run "'Copy of North TSC Format (2).xlsm'!PDFActiveSheet"
…etc.
changing what obviously needs changing in the code above.
If you know what the something and something else are you can write them into the code.
If they're liable to change, you can go to the source range of the data validation and iterate through those cells' values.
We'd need a bit more detail.