Hover Definitions let you customize the information in the popup that is shown to the user when they hover over a reservation on the calendar. You can not only display fields in this way, but also related lists.
Find the Hover Definition to edit
Go to the Reservation Display Contexts tab
Go to the 'All' listview, and find the row that you want to edit the hover for.
By default there is only one row in the Reservation Display Context list. If there are multiple and you're not sure which one to edit, check out this article for an explanation of how contexts are applied to reservations.
On the desired row, click on the record name in the Hover Definition column as pictured below:
Use the Hover Definition Editor component to add the fields that you want to display, both the hover fields and the Related list are supported.
The data is also stored in related objects under the hover definition. You can see the hover fields and the related lists as records in the system.
On the Hover Definition record, go to the Related tab and create Hover fields and Related Lists records to respectively add fields and related lists to the hover.
Adding Dynamic Flow Hover fields
Using the Dynamic Flow Hover Fields, you can use a Flow to dynamically calculate values to be displayed on the hover using data from the calendar where the Display Context is being used. While the Dynamic Flow Hover Fields are primarily intended for use with the Resource Display Contexts, they can also be used with the Reservation Display Contexts. Let us first take a look at how to create a compatible Flow for the Dynamic Flow Hover Fields:
Go to the Salesforce Setup, and open Process Automation > Flows. Then click on New Flow.
Navigate to the All + Templates tab and choose the Default Dynamic Hover Field Flow Template. Then click Next.
You can now create a flow using data available for a given resource for which the hover would be displayed. The following data is available in the Flow:
Start Date - The date and time at which the currently selected View on the calendar starts.
End Date - The date and time at which the currently selected View on the calendar ends.
View Name - The name of the currently selected View on the calendar.
List of Reservation IDs - For hovers over dimensions (such as resources) this will contain all the ids of reservations displayed on that row of the calendar. For hovers over reservations, this will contain only the id of the reservation being hovered over.
The result of the Flow should be stored in the variable 'outputField'. The value of this variable will be displayed on the hover.
Now that we have a valid Flow, we can move on to creating Dynamic Flow Hover Fields:
Navigate to the Hover Definition record and open the Related tab. In the top right corner of the Hover Fields related list, click New
Select the Static Hover Field and click Next.
For the Name field, you can fill in a name of your choice. For the Flow Name field, fill in the API name of the Flow that you wish to use.
For the Order field, choose any number. The lower the number, the higher the field will be in the hover popup.
Optionally, give the field a Label. This will be displayed in front of the field value in the hover popup. If you leave this field empty, it will default to the API name of the flow.