for the view history feature follow the link below, however may be just as easy to write changes to the field(s) concerned to the activity trail (worknotes) https://community.servicenow.com/community?id=community_question&sys_id=56098fa1db5cdbc01dcaf3231f96199c
All things ServiceNow... take a look at my channel: https://www.youtube.com/@cloudminus89