Hi Mohamed,
Thanks for the kind words!
We don't have that feature available in study view - within study view, the only option is to filter to TP53 mutant samples and then use the Custom Selection menu to select the currently unselected samples, which it sounds like is what you are doing.
Another option is to run a query for TP53 (or, if you want only TP53 mutations, use OQL to limit your query, eg query for 'TP53: MUT' ). When you run a query, the Comparison tab provides the same group comparison functionality as if you define groups in study view, but the groups default to altered samples (those with TP53 mutation) and unaltered samples (those without TP53 mutations).
-Tali