'Fields' variable does not show specified shapefile fields in Arcpy custom script

Question

I'm creating a script in ArcMap (ArcGIS 10.7.1).

I have created tool parameters to specify the workspace where the data is stored (Workspace), a shapefile displaying a boundary (Field boundary), a shapefile of soil points that will be interpolated (Soil points), and a few others (crop type, yield goal). Also to note, the soil points contain fields such as "Nitrogen", "Phosphorus", "Potassium", and a few others. I have verified their presence.

Below that, there is a field called "Nitrogen field" that should contain a list of all the fields that are found in the soil points shapefile, but they are not there when I open up the drop-down box. When setting up the tool parameters, I selected this parameter as a 'fields' data type, but nothing is there. How can I make these fields visible in the drop-down box?

Here's a picture of the tool parameter box to provide a better visual:

Answer 1

In your tool's 'Parameters' section, you need to select the field parameter ('Nitrogen field'), and then set its 'Obtained From' setting to be the feature class parameter from which the list of fields should be derived ('Soil points').