Manual:$wgActionFilteredLogs

Details
This allows logs to be filtered by log actions in Special:Log. See [ this link] for an example to filter delete logs by revision deletion actions. Each array key is a log type and it should be set to an array with the action groups which should be an array of  subtypes. The message keys are in the format:  . The label of the filter selection field comes from the message  . (For message documentation, you can use the doc-log-action-filter-type and doc-log-action-filter-action templates, respectively.)

Extensions with custom log types may add to this array.