You probably must declare custom delegate to match this criteria for it to work:
DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams( FForEachActorIteratorSignature, class AActor*, Actor, int32, Index );
DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams( FForEachAssetIteratorSignature, class UObject*, Asset, int32, Index );
Then when you bind them blutility should execute code you specified on them… I did not tested this yet but plan to use this so I’m drilling through source to look at what it have to offer. UE4 would benefit great deal from more usage examples/documentation 
Try to look here for some ideas what can be done:GlobalEditorUtilityBase.h