You can use functions to select members dynamically. After you select a function, you can edit its parameters. For more information on the dynamic use of functions, see Using the Formula Bar. For more information on editing function parameters, see Including a Member in a Function.
To assign members using functions:
Click the Add button, , to open the Edit (name) Function dialog box.
The Edit (name) Function dialog box is not displayed for functions that do not require parameter values, such as BottomofHierarchy, TopofHierarchy, AllMembers, and SuppressSharedMembers.
Double-click the Value column inside row 1, then edit its value by clicking the Lookup button.