Please have a look at the following case and let me know if you have a suggestion or work-around for this!
We have a classic account Financial Planning model with several dimensions: Profit Center, Cost Center, G/L Account (account dimensions), Date. Also, we configured Validation Rules for this model and would like to start planning and ultimately export the financial planning data to S/4 HANA. Planners should be able to plan data at any level, meaning that it should be possible to enter data at Profit Center level (set Cost Center to unassigned) and Cost Center level (select a Cost Center and its corresponding Profit Center). Validation rules check whether the selected level is a valid combination based on the Profit Center property in the Cost Center dimension.
The way Validation Rules determine whether unassigned is a valid combination is described as follows.
Meaning that an unassigned Cost Center is considered valid combination with a Profit Center, if there is existing combination with any other Cost Center for that certain Profit Center.
When we are planning data at Profit Center level, we have some Profit Centers that have no underlying Cost Center. Thus, the Validation Rules do not allow input. We were surprised by this, but SAP Support informed us that this designed behavior of the Validation Rules. We are looking for a workaround to be able to plan at Profit Center level while the validation rules are active.
Not sure about the following but it is possible to export data from SAC to S/4 HANA that is published to a Profit Center and unassigned Cost Center. EDIT: Confirmed by the comments.