This is very basic and common requirement and I am trying to map the same at my end. In pursuing so, I was following note#1615552 - Hot to Set User Default.
In this note, I came across with an action (in Step#2) to maintain User Default BRF+ Selection Rule. Below is the excerpt from note (Only step#2):
Step 2: Maintain the User Default BRF+ selection rule.
In transaction SPRO Open node Governance, Risk ad Compliance>Access Control>Maintain AC Applications and BRFplus Function Mapping and copy the BRF Function Id mentioned against 'User Defaults'
Now open transaction brfplus and choose menu Workbench>Open object and enter the id that you selected above (80E0ED08B0561DDFA5ADCADA787E1EDA).
Once the object is open, go to the Signature section an see that the 'Result Data Object' is USER_DEFAULT_ID.
Write your BRF+ rule so that a unique Id is returned in USER_DEFAULT_ID output structure that you mentioned already defined in step 1.
BRF+ rule will be based on the input structure supplied to the function which should be the base of determining what user id should be resulted out.
I opened object#80E0ED08B0561DDFA5ADCADA787E1EDA in BRF+ application and I found the USER_DEFAULT_ID as indicated in the note.
It asks to write own BRF+ rule for this user default. This has raised below 2 questions for me:
1. Should I create a new BRF+ application as I created for "Initiator Rule"?
If yes, then how should I create BRF+ application for User Defaults? I mean, like "Initiator Rule", do we have for "User Default" also?
2. Should I modify 80E0ED08B0561DDFA5ADCADA787E1EDA (standard) object?
If yes, then may I know how should I modify to reflect my user default parameters?