CDE, MDX and SQL with user visibility

I'm using Pentaho CDE and many users.
mdx with extracting data follows the profiling set.
with sql extracts all the data and are not those of user visibility.
What can I enter as a condition where will respect for profiling? (Where ${ })

how can I insert the condition: (Where $ {<user login in>}).
Which variable cde registered user login in?

Thanks in advance
Ettore