The submenu you leave open is the chosen filter.
Filters are only necessary if you want to hide the friendly tests you don't care about.
You can use a public filter, or you can make your own, called Quick, Alpha, Bravo and Charlie.
The Quick filter only excludes the main categories you choose.
In Alpha, Bravo and Charlie, you can exclude individual tests, subgroups or categories.
In Public you can choose a public filter. You need to ask for extra rights to make public filters.
Each test language and country subgroup has its own set of filters.
In Settings/Language you can select which languages or country subgroup to include in the active test language.