Drill to Transaction has been replaced with Drill to Source, which now encompasses two new additions of Metrics and Dimensions lists as sources.  Now you can easily identify the source data used in a calculation that originated in Dimension lists and Metrics. 

Right-click on a cell and select Drill to source, from there you can choose the block type you wish to dive deeper into. 

Through the use of automatically set page selectors, you will view all the Metric cells, or Transactions/Dimensions list items that were used in that cell's calculation.