Search log variables can be used within toplists of searches (when the logging switch is on).

{SEARCHVALUE} - The term being searched for.
{SEARCHCATID} - The category id which the search is restricted to.
{SEARCHDATE} - The date/time the search was performed.
{SEARCHMEMBERID} - The member id of the person who searched.

All member template variables will apply, with the values for the person who performed the search, using {SEARCH + member field + }.