We want to use the KPI Scorecard to simply show the balance of one bank account.  Hence, we believe we need to use a Custom KPI.  We created a Transaction Saved Search that uses Criteria of the Account.  We then output the Amount column and use a Summary function.  It perfectly shows the current balance in the Account.  We then added the 'Date' field in the Available Filters so that the KPI Scorecard system would know how to key on it.

The problem is that the KPI Scorecard is passing in the date but that only provides the transactions that happened that day.  We need it to include all the dates since inception to the current date.   Or use a criteria that says Today's date and older.  The available date filters appears to use "equals" as an operator.