Marcus, try using the following which uses the "DataMgmtCopyDataDefinition" class:  
                Dim returnValue As Object = args.DefaultReturnValue    
                Dim dmStepMetadataInfo As DataMgmtStepMetadataInfo
 
                If args.OperationName = BREventOperationType.DataManagement.ExecuteStep Then
                    dmStepMetadataInfo = DirectCast(args.inputs(0), DataMgmtStepMetadataInfo)
 
sbLog.AppendLine($"Destination Cube: {dmStepMetadataInfo.CopyDataDefinition.DestCube}")
sbLog.AppendLine($"Destination Entity Filter: {dmStepMetadataInfo.CopyDataDefinition.DestEntityFilter}")
sbLog.AppendLine($"Destination Scenario: {dmStepMetadataInfo.CopyDataDefinition.DestScenario}")
sbLog.AppendLine($"Destination TimeFilter: {dmStepMetadataInfo.CopyDataDefinition.DestTimeFilter}")
sbLog.AppendLine($"Destination View: {dmStepMetadataInfo.CopyDataDefinition.DestView}")
 
sbLog.AppendLine($"--------------------")
 
sbLog.AppendLine($"Source Cube: {dmStepMetadataInfo.CopyDataDefinition.SourceCube}")
sbLog.AppendLine($"Source Entity Filter: {dmStepMetadataInfo.CopyDataDefinition.SourceEntityFilter}")
sbLog.AppendLine($"Source Scenario: {dmStepMetadataInfo.CopyDataDefinition.SourceScenario}")
sbLog.AppendLine($"Source TimeFilter: {dmStepMetadataInfo.CopyDataDefinition.SourceTimeFilter}")
sbLog.AppendLine($"Source View: {dmStepMetadataInfo.CopyDataDefinition.SourceView}")
 
brapi.ErrorLog.LogMessage(si, sbLog.ToString)
End If
 
Here is the DM job used in the example and the log output.