Then look up source code how this node do it, it seems oyu need to get FFrame and from there call GetStackTrace()
https://github.com/EpicGames/UnrealEngine/blob/ab237f46dc0eee40263acbacbe938312eb0dffbb/Engine/Source/Runtime/Engine/Private/KismetSystemLibrary.cpp#L30
https://github.com/EpicGames/UnrealEngine/blob/ab237f46dc0eee40263acbacbe938312eb0dffbb/Engine/Source/Runtime/CoreUObject/Private/UObject/ScriptCore.cpp#L414
There also seem to be more global version which is static function:
Note that this only give you VM that powers blueprints call stack not native CPU call stack