Light Propagation Volume Settings
Some global settings can be found in the post process settings (add a post process volume, make it unbound
and make sure it has a proper priority):
The tooltips (hover over with the mouse) give you more details on the settings.
Having those settings in a volume allows them to be soft blendable depending on the camera position (e.g.
less GI bounce in an indoor environment or under some trees).
Secondary occlusion should be enabled, and since secondary bounces are very cheap, they should also be enabled.