A static function for unloading would be handy. Something like:
void UnloadLevel()
{
FString LevelName = LevelStreamKismet->GetWorldAssetPackageName();
LevelName.RemoveFromStart(FString("/Game/<I keep my levels here>/uedpie_0_"), ESearchCase::IgnoreCase);
UGameplayStatics::UnloadStreamLevel(this, *LevelName, LatentInfo);
}