if I now understand you correctly you are indeed looking for changes to specific issues.
There is not perfect news - you can search but not by means of 'everything user x changed for the last y days'
Basically, without repeating all information already to be found in Community, kindly compare with an older thread - this still applies:
Hello Community! We thoroughly enjoyed this just-for-fun conversation in the Jira Admin Group about what it's like to be a Jira Admin. For #JiraJuly, our talented designers created these graphics t...
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