Hi Raymund,
Please check the online help for portfolio transfer. It describes the prerequisite to execute TPM82.
Portfolio Transfer - Accounting - SAP Library
You can use the portfolio function to transfer securities positions that
are differentiated by portfolio to other portfolios.
(Customizing : General Settings→ Accounting → Settings for Position Management→ Define and Assign Differentiations. )
This is only used for securities positions, and not possible for OTC positions.
Hope this helps.
Best regards,
Jasmine