In order keep configuration simple, please perform the following steps in Salesforce Classic (Booker25 is Lightning-Ready, you may afterwards use the app in Salesforce Lightning as you please)
I you have custom calendars you might want to introduce some more structure by grouping your dimension object. for example on a contact calendar grouping contacts by account.
To do this you can create one or more Dynamic Grouping Fields related to the calendar you want to group objects on.
example the resource calendar with no grouping :
and with a Hierarchical B25__Parent__c grouping:
Dynamic Grouping Field
Field name
description
Name
The name of the field on the dimension object that the object should be grouped by.
Label
The label users should see in the picklist where they can select what grouping to use leave blank for the label of the field.
Calendar
The calendar this grouping belongs to.
Default
If this grouping should be selected by default, If no default is specified the first selected grouping is random but deterministic
Hierarchical
If this setting is enabled the Name should refer to a self-referencing field and booker25 will group the
NoGrouping
Marks this grouping as no grouping at all. This wil also disable the validation on the name field so it can be anything.