How to do it...

1. Create a new Actor class in the editor called PropertySpecifierActor:

2. Add the following property definitions to the class:

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "PropertySpecifierActor.generated.h"

UCLASS()
class CHAPTER_09_API APropertySpecifierActor : public AActor
{
    GENERATED_BODY()
    
public: 
    // Sets default values for this actor's properties
    APropertySpecifierActor();

protected:
    // Called when the game starts or when spawned
    virtual void BeginPlay() override;

public: 
    // Called every frame
    virtual void Tick(float DeltaTime) override;

    // Property Specifiers
    UPROPERTY(EditDefaultsOnly)
    bool EditDefaultsOnly;

    UPROPERTY(EditInstanceOnly)
    bool EditInstanceOnly;

    UPROPERTY(EditAnywhere)
    bool EditAnywhere;

    UPROPERTY(VisibleDefaultsOnly)
    bool VisibleDefaultsOnly;

    UPROPERTY(VisibleInstanceOnly)
    bool VisibleInstanceOnly;

    UPROPERTY(VisibleAnywhere)
    bool VisibleAnywhere;
};

3. Perform a Save, Compile your code, and launch the editor.
4. Create a new blueprint based on the class.
5. Open the blueprint and look at the Class Defaults section:

6. Note which properties are editable and visible under the Property Specifier Actor section:

Location of the Property Specifier Actor

7. Place instances in the level and view their Details panels:

8. Note that a different set of properties is editable.