Trying to figure out the search syntax here.
1. Searching by template
2. Document Type is SOW
*3. Search for all documents with this template and doc type, where the "stage" field is NOT BLANK.
You should also be able to do what you want to do by simply adding a * into the Stage field.
You can use the <> operator in an advanced search to restrict results to only values that do not match the specified string.
{[Professional Services Documentation]:[Stage]<>"", [Document Type]="SOW"}
In this case, I've told search to find me all PSD documents that have a Document Type of SOW, but have a Stage field that is not blank.
Remember that you can mix and match advanced search syntax with regular searches.
Here is an equivalent search done with only advanced search:
Here is one where I've selected some parameters using the conventional search, and then I've added in only the advanced search syntax that looks for a non blank value.
Thank you both for the help! The operator * worked for exactly what I needed. The search syntax was very helpful as well.