https://www.telerik.com/kendo-jquery-ui/documentation/api/javascript/ui/chat/configuration/receivermessagesettings.allowmessagecollapse
receiverMessageSettings.allowMessageCollapse - API Reference - Kendo UI Chat - Kendo UI for jQuery
In this article you can see how to configure the receiverMessageSettings.allowMessageCollapse property of the Kendo UI Chat.
api referencekendo uichat forallowmessagecollapsejquery