Hi @Saikat001
There are two ways that i could think of, you can write a custom script to read through and write the hosts and csv filenames.
Splunk way if only CSV are same structure otherwise you have to normalize the fields takes good amount of time give csv's are too many, ingest 1000+ csv to splunk using UF and write a SPL to find the hostname details by source. Your source is csv filename.
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An upvote would be appreciated if it helps!