Just thought I would add what I did to resolve this issue.
I created a parameter, of type Member List
I set the Display Items and Value Items (comma delimited) as a call to an XBFR rule: XFBR(XFBR_Member_List, SP_Source_Scenario_List,PoVTime=|WFTime|)
I set my Combo Box, Bound Parameter to the previously created parameter
In my XFBR rule I return the list like this...
Dim POVWorkflowTime As String = args.NameValuePairs.XFGetValue("PoVTime")
Dim memberFilter As String = "S#SpendPlanControl.Base.Where(Name DoesNotContain Working)"
Dim ScenarioLists As List (Of MemberInfo) = BRApi.Finance.Metadata.GetMembersUsingFilter(si, "S_BudEx", memberFilter, True)
Dim memberString As String = String.Empty
For Each scenarioMbr In ScenarioLists
Dim ScenarioMember As MemberInfo = BRApi.Finance.Metadata.GetMember(si, DimType.Scenario.Id, scenarioMbr.Member.Name, True)
Dim ScenarioMemberID As Integer = ScenarioMember.Member.MemberId
'Get Scenario member property WorkflowTime for comparison
Dim scenarioListWorkflowTime As String = ScenarioMember.GetScenarioProperties.WorkflowTime.GetStoredValue.ToString.Substring(0, 4)
Dim scenarioListWorkflowStartTime As String = ScenarioMember.GetScenarioProperties.WorkflowStartTime.GetStoredValue.ToString.Substring(0, 4)
Dim scenarioListWorkflowEndTime As String = ScenarioMember.GetScenarioProperties.WorkflowEndTime.GetStoredValue.ToString.Substring(0, 4)
'Compare Scenario List Workflow time to POV Workflow Time
If scenarioListWorkflowTime = POVWorkflowTime Then
memberString = memberString & scenarioMbr.Member.Name & ","
End If
Next
Return memberString