I made few test payments by taking user credentials for a particular website. I do not see any count of them in my dashboard. Those payments are actually pending so does pending transactions count is shown in dashboards by default or not? I am sure I created BT correctly.
The business transactions will likely have no visibility into the state of something like a payment after it is made. If you have created this BT by say creating a filter that looks for a /payment web request or a payment() method then the BT will be a bucket of those PurePaths.
Can you describe or preferably post a screenshot of you BT configuration as well as the "filter" measure you are using. If you're not seeing any data a common cause is the filter not having a threshold defined which is necessary for such a BT to work.