The current method of displaying groupby criteria is to use the IGroupByCriteria utility. This is a global utility that caches its results. However, as it is a global utility it is caching results across the instance and there is no separation of sites. So if you have an instance with multiple sites, the cache will be whichever one gets processed first meaning it will break collection filters for other sites. It is also then sharing information about the indexes between sites which is a security concern.

The code in question:

Possible solution:

Instead of caching on the utility, use memoize with the site path as the key.

I'm currently working on a PR for this, but any other input/ideas are welcome @petschki, @thet