Ontolica Aggregate farm level configurations are done in Central Administration > General Application Settings >Manage Ontolica Modules > Manage Aggregate Configuration. Here you can find configuration pages with default property settings for search result actions and also searchable, search result as well as refiner properties that will be used by all Ontolica Aggregate Centers in your farm. In addition to default properties you can also define custom properties. Site collections and sites in Web applications, where you deployed the Ontolica Search solution, will also have those configuration settings in their Site Settings pages. Lower level configurations inherit settings from higher levels, which means that custom properties defined at the farm level will be available at the site collection and site levels. Those settings can be overwritten in lower levels.