For those working with hub sites in SharePoint you have for a long time used the managed property DepartmentId, later accompanied by RelatedHubSites when hub site hierarchies was enabled.
Now the time has come to have these properties, and some more, added to the public documentation.
Take a peek at https://learn.microsoft.com/en-us/sharepoint/crawled-and-managed-properties-overview which covers these new properties available for online experiences.
The documentation UX is not ideal, so ensure you scroll the table of properties to the right to read the comments per property. Here’s a copy of the table for reference where I moved the comment for visibility.
Note the (*) highlighting that it’s not guaranteed that each item has a value in the property.
| Property name | Type | Comment | Multi-valued | Queryable | Searchable | Retrievable | Refinable | Sortable | Mapped crawled properties |
| DepartmentId | Text | Site ID of the hub of the immediate hub. Applies to all items in the hub/associated sites. | No | Yes | No | Yes | Yes | No | ows_DepartmentId |
| RelatedHubSites | Text | Site IDs of associated hubs including hub hierarchies. Can be used instead of DepartmentId for most scenarios. Applies to all items in the hub/associated sites. | Yes | Yes | No | Yes | No | No | ows_RelatedHubSites |
| IsHubSite | Yes/No | Applies to the site result of a hub (contentclass=STS_Site) | No | Yes | No | Yes | No | No | ows_IsHubSite |
| ModifierAADIDs | Text | Semi-colon separated list of AADIDs for modifiers of a file or page ordered in date descending order. (*) | Yes | Yes | No | Yes | Yes | Yes | |
| ModifierDates | Date and Time | Semi-colon separated list of modification dates for modifiers of a file or page ordered in date descending order. (*) | Yes | No | No | Yes | No | No | |
| ModifierNames | Text | Semi-colon separated list of the names for modifiers of a file or page ordered in date descending order. (*) | Yes | Yes | No | Yes | No | No | |
| ModifierUPNs | Text | Semi-colon separated list of UPNs for modifiers of a file or page ordered in date descending order. (*) | Yes | No | No | Yes | No | No | |
| ChapterTitle | Text | Semi-colon separated list of auto-generated chapters on Teams meeting videos. (*) | Yes | Yes | Yes | Yes | No | No | ChapterTitle |
| ChapterOffset | Text | Semi-colon separated list of time codes matching the chapter titles for auto-generated chapters on Teams meeting videos. (*) | Yes | No | No | Yes | No | No | ChapterOffset |
* Property is not guaranteed to contain data.
