You see all components that are visible to you.
In other words, it depends on the ownership for each component.
- Any component owned by the project area or your Team Area would be displayed in the Component section.
- Any component owned by a single resource (a member of the RTC project area) or another Team Area (that you aren't part of) won't be displayed there.
The same would apply for the streams: check the owner of those streams to understand why a resource doesn't see it.
Whats the point of hiding a stream if the components themselves are not hidden ?
The point (in hiding Stream even though it doesn't hide component) is preventing users to deliver to that stream: they can still work on the same set of component (visible because of the right ownership), but they can no longer see (and deliver to) a given Stream.