In Event Timeline viz app the group column needs to be sorted based on time, currently it’s based on alphabetical order.
@yadavshilpa you can refer to the Event Timeline Viz App update the app developer @danspav has made in order to fix this issue
https://answers.splunk.com/answers/752660/in-event-timeline-viz-app-the-group-column-needs-t-1.html
There is also a workaround I have provided through query where you can give number to your group field and ensure that all groups are always present (in case a group is missing add NULL value).
Can you add more context and be more thorough in what you are trying to ask. That'll help people help You better.
Thanks