No, no search function that I know of.
Connect to the device, better if using Winbox.
Then follow these instructions to export configuration:
http://forum.mikrotik.com/t/forum-rules/173010/1
then open It in Notepad or any text editor and search for them.
Alternatively in Winbox Terminal try using [TAB] auto-completion, i.e. type:
/interface wi[TAB]
and see what options you are given, and navigate through either wireless or wifi …