I have a map of sets containing ids -
Map<String,Set<Id>> caseIdsByFlag = new Map<String,Set<Id>>();
& I'm trying to access the values in the map's sets in an SOQL query
List<CaseMilestone> caseMilestones = [SELECT Id, CompletionDate FROM CaseMilestone WHERE CaseId IN :caseIdsByFlag.values()];
But that's causing an error
Invalid bind expression type of Set for column of type Id
Is it possible to access the values from a map of sets in an SOQL query?