The self_link filter allows you to manipulate the link for the currently displayed feed.
When the 'self_link' filter is called, it is passed one parameters: the link.
add_filter( 'self_link', 'filter_function_name', 10, 3 );
function filter_function_name( $link) {
// Manipulate link
return $link;
}
Where 'filter_function_name' is the function WordPress should call when filter is run. Note that the filter function must return an value after it is finished processing or the result will be empty.
filter_function_name should be unique function name. It cannot match any other function name already declared.