It's not exactly clear what you mean by 'drop down' menu.
In any case, if you add a pivotal table chart or other non straight table items to the template editor field list on the top left of the template editor, the individual field values in the pivot or other non-straight table charts will not be available to drag and drop to the template editor.
In order to expose the individual fields of an QV Chart Object accessed from NPrinting (anything that is not a straight table), you must first clone and then convert the object to a straight table in Qlikview and save the QVW.
You then need to refresh the object cache and then search for the new QVW object number.
This new object can now be expanded to show the individual fields.
What can you do with a QV straight table in NPrinting? See a couple article below:
How to Create a Pivot Table from Excel Table Columns
How to Add Levels in Excel Reports
Developer Knowledge base
I am guessing when you say drop down you are referring to the '+' sign on the left protion of the template? As Frank said, you can only expand a table to see all of the columns if it is a straight table with QlikView - pivot tables will show in the Table portion of the template, but you cannot expand the table to see the columns.
Regarding bar charts, those typically have to be dimension fields but if you could attach a copy or a test copy of an application containg a chart with the issue I would be more than happy to take a look at it further