In CommandUI versions prior to 1.10.0, some search scopes‘s items where hidden from search, mainly for performance reasons, until you selected the parent scope.
This is now now longer required, and you can search all your content immediately after opening CommandUI with the default hotkeys.
This is difference is best understood with a few real examples.
v1.9.0: No results when searching for posts in the root search.
v1.9.0: You had to go explicitly into the “Post Types” scope, to start searching for dynamic content.
v1.10.0: All posts (and other CPTs) are now available directly in the root search.
v.1.10.0: All users can be directly searched from the root, without going into the user scope.
