Add this code in `functions.php`

    function custom_rewrite_rule() {
    
    	//Initializing Rewrite Tags
    	add_rewrite_tag('%begin-date%', '([^&]+)');
    	add_rewrite_tag('%end-date%', '([^&]+)');
    	add_rewrite_tag('%offset%', '([^&]+)');
    
        //Find page rewrite rules
        add_rewrite_rule('^find/([^/]*)/([^/]*)/([^/]*)/?','index.php?page_id=<SEARCH_PAGE_ID>&begin-date=$matches[1]&end-date=$matches[2]&offset=$matches[3]','top');
        add_rewrite_rule('^find/([^/]*)/([^/]*)/?','index.php?page_id=<SEARCH_PAGE_ID>&begin-date=$matches[1]&end-date=$matches[2]','top');
    
        flush_rewrite_rules();
    }
    add_action('init', 'custom_rewrite_rule', 10, 0);

On your custom search page template

    $begin_date = get_query_var('begin-date');
    $end_date   = get_query_var('end-date');
    $offset     = get_query_var('offset') ? get_query_var('offset') : 1;


Create a page having slug `find` and apply a custom page template over it .. replace `<SEARCH_PAGE_ID>` with the newly created page ID and update the permalink structure!

Use these values in your custom query in the page template! :)