Cloud - is it possible to filter a Group by a search context?

Basically I tried like below and all kinds of variations of it but it somehow never took the Contract parameter from the search context it was always NULL.

However, I have a List on this page as well and the same thing that works for that.

So is it possible at all to filter a Group using a search context?

searchcontext WagePageSearchContext bind LaborClassSelector {
   defaults = GetWagePageSearchContextDefaults();
}

selector LaborClassSelector;
group LaborClassGroup using GetLaborClassRows(searchcontext.WagePageSearchContext.Contract);