i have a custom tag which fires on a specific event and there is some data that gets updated just for this event. This informaiton is not present in the utag_data only in the b object.
Now i need to access this in my custom tag to retrieve the event specific data to send it to a callback function.
If you know that the data is available in the "b" object, you can reference it using b.variable_name. You can add this reference anywhere in the tag template that you need the variable's value.