If you are a Chrome User, this extension is pretty handy:
Show Field ID extension
Basically, you hover over a field and then it tells you its name, e.g. tranid for Transaction ID. You can then use the Formula function in NS Saved Searches to display the field. For example, {customer.category} will display the Customer Category for a search return, even in a transaction search.
And, you can do some nice logic on it for the display using a Formula :
CASE WHEN {customer.category} is NULL THEN '-Unassigned-' ELSE {customer.category} END