Hi Daniel Schwarze,

You can consider customizing the Widget Template to display additional information within the many2many_checkboxes widget for splitting transactions in Odoo. This approach utilizes existing Odoo widget options to enhance the information displayed in the checkboxes. But it requires knowledge of Odoo's templating system (QWeb)

For this consider the following steps.

• Use the no_label option with the many2many_checkboxes widget to hide the default label (order number). This allows you to create a custom display for the checkboxes.
• Create a custom QWeb view that displays the desired information (amount, bank account, description, payment date) for each related account.payment.order record.
• Within your custom QWeb view, use the widget option to render a custom widget that displays the checkbox and the additional information retrieved from the related record.

Hope this helps.