Pivot Table - Sorting the whole table based on additional V-Look Up Data

[Steve1977]

Basically I have a Pivot Table and got a few V LookUps in subsequent columns.

Now I want to sort the whole Pivot Table based on the extra Column which contains V-LookUp Data but it's all greyed out.

So I thought, let's just add the relevant field to the Pivot Table but then it just goes right across the screen with every possible value rather than the one specific to the part number on that line.

Any help would be most welcome