New documentation available at https://docs.openkm.com/kcenter/
The documentation at the https://www.openkm.com/wiki is definitivily deprecated.
Consider only use it, if you are user of OpenKM version 6.2 and older.
Click in the banner to close the warning.
Activity log tab allows you to see document, folder or email logs.
You can view all or filtered logs for the selected document, folder or email. The View get childs option filters the get childs action, because that's one of the most common.