Per the documentation for WP_User_Query, there is an available search parameter. It looks something like this:
$users = new WP_User_Query(array(
'search' => 'This is my search'
));
You can even set the columns in the database that are searched against using the "search_columns" parameter like so:
$users = new WP_User_Query(array(
'search' => 'This is my search',
'search_columns' => array( 'user_login', 'user_email' )
));
Now, the documentation mentions that you can modify the different columns available for search using the user_search_columns
filter. That filter is defined on this page:
Filter Reference/user search columns
I don't see anything about searching based on usermeta though. I want to add usermeta as a search column. Does anybody know how to do this?