Create Blueprint Enum

Fill Enum with values

Create new C++ class

UCLASS()
class UClassName : public UUserWidget
{
	GENERATED_BODY()

};

Create FName property and TArray<FName> property

UCLASS()
class UClassName : public UUserWidget
{
	GENERATED_BODY()

public:
	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = "CategoryName")
	TArray<FName> Categories;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "CategoryName", meta = (GetOptions = "Categories"))
	FName Category;

};

Create constructor

UCLASS()
class UClassName : public UUserWidget
{
	GENERATED_BODY()
	
	UClassName();

public:
	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = "CategoryName")
	TArray<FName> Categories;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "CategoryName", meta = (GetOptions = "Categories"))
	FName Category;

};

Fill constructor with load code

UClassName::UClassName()
{
	FString EnumPath = TEXT("/SkillTree/Enums/E_SkillTree_Categories.E_SkillTree_Categories"); // 

	UEnum* LoadedEnum = Cast<UEnum>(StaticLoadObject(UEnum::StaticClass(), nullptr, *EnumPath));

	if (LoadedEnum)
	{
		for(int32 i = 0; i < LoadedEnum->GetMaxEnumValue(); i++)
		{
			Categories.AddUnique(FName(*LoadedEnum->GetDisplayNameTextByIndex(i).ToString()));
		}
	}
	else
	{
		UE_LOG(LogTemp, Error, TEXT("Failed to load enum at path: %s"), *EnumPath);
	}
}