Payflow does not have an option to split payments between two Business Accounts without submitting two different API Calls with two different sets of Payflow Credentials in the API Calls.
There is another option, based on the information provided in this post, the Managed Path in PayPal for Marketplaces would be a good option for your Business Model. The Managed Path uses Rest APIs, which will work with an App to take a payment from a customer and disperse the payment between your partner fee, and a merchant account. This is for PayPal Payments.
Information on PayPal For Marketplaces:
PayPal For Marketplaces Managed Path
Thanks,
Jennifer
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