Version blending is functionality that brings actual figures to be visible in the forecast versions. Each forecast element in the Version dimension can be configured in the Actual Months attribute to contain actual figures for the first given number of months, starting with January.
Here we could see that versions have 3,6,9 months of actual data for corresponding forecast versions. This can be achieved if in the version dimension we add the attribute Actual Month. [is already there if you use Version template dimension when creating].
After that rule needs to be set on the cube level.
Here is a good description of this feature in Jedox Knowledge Base.
Also, you can download the mini-project of version blending from here.