How can I get components declared in C++ to show up in components tab in BP editor?

Got it from 's solus c++ tutorial, sound like what you’re looking for

#include "Components/ActorComponent.h"
#include "YourClass.h"

UCLASS(ClassGroup = Group, meta = (BlueprintSpawnableComponent))
class OVERFLOW_API UOF_PawnComponent : public UActorComponent
{
	GENERATED_UCLASS_BODY()

	
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Stuff)
		float Whatever;
}

it makes a new entry for “YourClass” in a group called “Group” in the component tab