You can configure and create Braintree custom fields by following this article: https://developer.paypal.com/braintree/articles/control-panel/custom-fields
In order for us to pull in this custom fields information, you will need to add custom fields in Salesforce for our corresponding object. The field must be named as the "API Name" in Braintree + prefixed with 'cf_'. Depending on your Salesforce configuration, you may also need to add these new custom fields to a permission set so we can read and update the values in Salesforce.
We currently support custom fields for customers and payments. The example below will demonstrate how to set this up for a customer record, but the payment object is the same.
Here is a screenshot of a custom field creation in Braintree.
Here is a screenshot of a customer in Braintree
To pull this information into Salesforce, you will need to add a custom field to the BWP_Customer object. The Field Names for these will need to be named "cf_other_email". When creating the fields, the DataType should be 'Text' with a length of 255 characters.
API name must be less than or equal to 255 characters and can't contain any spaces or capital letters.