It sounds like you want to extract fields from your data. This is assuming you are already ingesting it into Splunk. Depending on the type of data, you should always check splunkbase.com first to see if there is an app or add-on for that data source. The add-ons will have the field extractions done for these sources. If it is something custom or there isn't an add-on available, you can extract fields through the GUI see docs here.