Custom Field Usage Finder
A handy tool to find out where a given custom field is used, this page may be accessed from the "Add-Ons" -> "Kepler Tools" section, menu "Custom Field Usage".
The tool simply consists of an autocomplete box, where you can start typing your customfield name or alias. Upon selection, the results of the search - if any - will be shown below.
You may navigate directly to the files by following the links.