“Sections” are what the editor calls the filter buttons which can be found in the Details panel, such as “General”, “Actor”, etc.
The code below allows you to add new custom sections into it.
.cpp
//Add this code to your Actor or whatever class constructor.
#if WITH_EDITOR
#define LOCTEXT_NAMESPACE "Custom Detail"
static const FName PropertyEditor("PropertyEditor");
FPropertyEditorModule& PropertyModule = FModuleManager::GetModuleChecked<FPropertyEditorModule>(PropertyEditor);
//Change "Actor" for the type of your Class(eg. Actor, Pawn, CharacterMovementComponent)
//Change "MySection" to the name of Desired Section
TSharedRef<FPropertySection> Section = PropertyModule.FindOrCreateSection("Actor", "MySection", LOCTEXT("MySection", "MySection"));
//You can add multiples categories to be tracked by this section
Section->AddCategory("MyCategory");
#undef LOCTEXT_NAMESPACE
#endif.h
// Now declare your variable normally, but use the Category with exactly what you defined on
// the track (Section->AddCategory("MyCategory");)
UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "MyCategory")
int32 MyVariable;