I have a csv file containing the SAM accounts of 1200 AD groups and I need to find out the proper search query to find the last date of their modification or change.
| inputlookup <lookup or filename>
| stats max(<field that's the date field>)
or
| inputlookup <lookup or filename>
| stats max(<field that's the date field>) BY displayName
And if you were wanting a more useful way
base search here that returns regular data
| lookup <lookupName> <fieldInLookup> AS <fieldInData> OUTPUT lastUpdate
Which assuming you fix up the lookup name, double-check the fieldInLookup vs. fieldInData order (I always get those backwards!) and change the fieldname 'lastUpdate' to whatever it is in your lookup, will output the lastUpdate for each ... "field" you match on. Perhaps displayName or something, whatever it is that should match.
This might help:
https://docs.splunk.com/Documentation/SplunkCloud/8.2.2107/SearchReference/Lookup