NtNotifyChangeMultipleKeys - NtDoc

Native API online documentation, based on the System Informer (formerly Process Hacker) phnt headers
#ifndef _NTREGAPI_H

NTSYSCALLAPI
NTSTATUS
NTAPI
NtNotifyChangeMultipleKeys(
    _In_ HANDLE MasterKeyHandle,
    _In_opt_ ULONG Count,
    _In_reads_opt_(Count) OBJECT_ATTRIBUTES SubordinateObjects[],
    _In_opt_ HANDLE Event,
    _In_opt_ PIO_APC_ROUTINE ApcRoutine,
    _In_opt_ PVOID ApcContext,
    _Out_ PIO_STATUS_BLOCK IoStatusBlock,
    _In_ ULONG CompletionFilter,
    _In_ BOOLEAN WatchTree,
    _Out_writes_bytes_opt_(BufferSize) PVOID Buffer,
    _In_ ULONG BufferSize,
    _In_ BOOLEAN Asynchronous
    );

#endif

View code on GitHub
#ifndef _NTZWAPI_H

NTSYSCALLAPI
NTSTATUS
NTAPI
ZwNotifyChangeMultipleKeys(
    _In_ HANDLE MasterKeyHandle,
    _In_opt_ ULONG Count,
    _In_reads_opt_(Count) OBJECT_ATTRIBUTES SubordinateObjects[],
    _In_opt_ HANDLE Event,
    _In_opt_ PIO_APC_ROUTINE ApcRoutine,
    _In_opt_ PVOID ApcContext,
    _Out_ PIO_STATUS_BLOCK IoStatusBlock,
    _In_ ULONG CompletionFilter,
    _In_ BOOLEAN WatchTree,
    _Out_writes_bytes_opt_(BufferSize) PVOID Buffer,
    _In_ ULONG BufferSize,
    _In_ BOOLEAN Asynchronous
    );

#endif

View code on GitHub

This function is documented in Windows SDK.