In Octane GUI, there are no ways to show/filter all the runs (like it exists on ALM.net).
It would be great to have it.
One of the reasons former ALM users/new Octane users are having trouble adopting manual testing in Octane is that the run data must be drilled down into one-by-one for each test/test suite. It would be easier for Octane users to monitor sprint/cycle specific testing if there was an overview tab for runs with ability to filter, sort, etc as you can for other entities.
When you filter tests by release in Octane today, we actually filter the runs of the test (whether they're planned or already executed or don't exist), so sounds like the behavior is according to what you would expect even though the relation between test and release is not direct.
If there is a specific widget/view that you'd like to see and is not available, please share the details.