How to index a field where identical values have different values for ID?

[AlexeyPy]

How to index the same field "A" different values for the unique ID? A set of field "A" values is finite and for each ID can have multiple identical field values.

After a few search strings I have a table. I try to explain by img:

My main difficulty that I can't calculate the time difference between any two points of the field "A", because there are the same field "A" values. I think that this way will help me.

[lfedak_splunk]

Hey @AlexeyPy, If DalJeanis solved your problem, please don't forget to accept an answer! You can upvote posts as well. (Karma points will be awarded for either action.) Happy Splunking!

[DalJeanis]

Try this...

 | sort 0 _time ID fieldA
 | streamstats current=f last(_time) as priortime by ID fieldA
 | eval duration=coalesce(_time - priortime,"No prior")

[AlexeyPy]

Unfortunately, that's not what I need. I need to be able to calculate the difference in time between those points, which I want. In this search only between the first and last in the group