The below link provides the information on activating the virtual time hierarchies in BEx.
http://help.sap.com/saphelp_nw73ehp1/helpdata/en/1f/83813ec8d3fe3ee10000000a114084/frameset.htm
We can also use Tcode RSRHIERARCHYVIRT for the same.
The below link provides the information on activating the virtual time hierarchies in BEx.
http://help.sap.com/saphelp_nw73ehp1/helpdata/en/1f/83813ec8d3fe3ee10000000a114084/frameset.htm
We can also use Tcode RSRHIERARCHYVIRT for the same.