UAssetEditorSubsystem
The UAssetEditorSubsystem subsystem is very useful to get some data/events linked to assets.
Its initialized in UEditorEngine::InitializeObjectReferences (called in FEngineLoop::Init → UUnrealEdEngine::Init).
Example on how to open a BP from a sub object component object
auto* AssetSS = GEditor->GetEditorSubsystem<UAssetEditorSubsystem>();
AssetSS->OpenEditorForAsset(OutSelectedObject, AssetTypeActivationOpenedMethod::Edit);