GetPreviousPeriod
Use this function to return the previous symbol in the hierarchy which is a sibling of the specified symbol (if SymName is the first symbol, then a blank is returned).
where:
SymName is the name of a symbol in the time periods dimension. The symbol must be a descendent of a symbol specified in either the SGPTimePerActivity or SGPTimePerYTD attributes. For more information on attributes, see the Longview Application Administrator Guide.
Note: GetPreviousPeriod returns an error message if the user does not have access to that particular symbol.