1. Click "Grid"
2. Select your "Category" and "Filter"
3. Click "Edit"

The "Edit Filter" screen will open.
1. Click Edit Columns

You will now have the ability to add the fields you wish to include in your Grid column headers:

1. Available headers by category
2. Search option for specific fields you are looking for
3. Fields under the Visible headers are what is currently showing in your Grid column headers.
4. Once you have all of the desired headers, click "Save".