How to modify FinApIncompleteInvoiceHold rules
I would like to modify predefined "Incomplete Invoice Payables User" participant in FinApIncompleteInvoiceHold BPM task. I need to change the assignee type from "Rule-based" to "Names and expressions" but this field is not enabled for editing (unlike to other BPM tasks). Alternatively I could add a new assignee with type "Names and expressions" but the icon for creating a new participant (in top right corner of the existing participant box) is not available at all.
The business reason for this is to assign incomplete scanned invoices to specific user according to group of suppliers. My idea is to enable DFF at Supplier Header to store Supplier Group information and then create lookup set to assign users to Supplier Groups. Finally I would use SQL command to get user in expression field of participant.