Display a pagination for custom admin panel query mostly with WordPress styling.

tutsnano-admin-page-query-2.php

<?php
$posts_per_page = get_option( 'posts_per_page );
$paged = $_GET['paged'] ? $_GET['paged'] : 1;
$tutsnano_page_query = new WP_Query(
                        array(
                          'post_type'       => 'page',
                          'post_status'     => 'publish',
                          'posts_per_page'  => $posts_per_page,
                          'paged'           => $paged
                        )
                      );

while( $tutsnano_page_query->have_posts() ) : $tutsnano_page_query->the_post();
//displaying the query data as per choice
endwhile; wp_reset_postdata();

//display the pagination here
tutsnano_admin_query_pagination( $tutsnano_page_query, $posts_per_page, 'admin.php?page=my_page_slug' );

tutsnano-admin-page-query.php

<?php
$posts_per_page = get_option( 'posts_per_page );
$paged = $_GET['paged'] ? $_GET['paged'] : 1;
$tutsnano_page_query = new WP_Query(
                        array(
                          'post_type'       => 'page',
                          'post_status'     => 'publish',
                          'posts_per_page'  => $posts_per_page,
                          'paged'           => $paged
                        )
                      );

tutsnano-admin-query-navigation.php

<?php
/**
 * Admin query navigation.
 *
 * Display a pagination for custom admin panel query mostly
 * with WordPress styling.
 * 
 * @author Christine Cooper
 * @author Mayeenul Islam
 * @link   http://wordpress.stackexchange.com/a/175649/22728
 * @link   http://tuts.nanodesignsbd.com/en/paginate-custom-wp-query-in-admin-end/
 * 
 * @param  string $query     		Query object.
 * @param  integer $items_per_page    	Posts per page.
 * @param  string $page_path 		The page where query is executed.
 */
function tutsnano_admin_query_pagination( $query = '', $items_per_page = '', $page_path = '' ) {

    if( empty($query) )
        return 'Query must be set';

	$total_pages = (int) $query->max_num_pages;
    //as get_query_var() won't work in admin end
	$paged = $_GET['paged'] ? (int) $_GET['paged'] : 1;
	$nextpage = $paged + 1;
	$prevpage = max( ($paged - 1), 0 ); //max() to discard any negative value
	
    //assumed, we're using the default posts_per_page value in our query too
	$items_per_page = empty($items_per_page) ? (int) get_option( 'posts_per_page' ) : (int) $items_per_page;
	$lastpage = ceil( $query->found_posts / $items_per_page );

	if( empty($page_path) )
		return _e( 'Admin path is not set' );

    //adding 'paged' parameter to page_path
	$next_page_path = add_query_arg( 'paged', $nextpage, $page_path );
	$prev_page_path = add_query_arg( 'paged', $prevpage, $page_path );
	$lastpage_path  = add_query_arg( 'paged', $lastpage, $page_path );

	echo '<div class="tablenav bottom">';
		echo '<div class="alignleft">';
            //Display the 'Previous' buttons
			if( $prevpage !== 0 ) {
			    echo '<a class="button button-default" title="First page" href="'. $page_path .'">&laquo; <span class="screen-reader-text">First page</span></a> ';
			    echo '<a class="button button-primary" title="Previous page" href="'. $prev_page_path .'">&lsaquo; <span class="screen-reader-text">Previous page</span></a> ';
			}

            //Display current page number
			if( $paged !== 1 && $paged !== $total_pages ) {
				echo '<span class="screen-reader-text">Current Page</span>';
				echo '<span id="this-page">'. $paged .'</span>';
			}

            //Display the 'Next' buttons
			if ($total_pages > $paged) {
			    echo ' <a class="button button-primary" title="Next page" href="'. $next_page_path .'"><span class="screen-reader-text">Next page</span> &rsaquo;</a>';
			    echo ' <a class="button button-default" title="Last page" href="'. $lastpage_path .'"><span class="screen-reader-text">Last page</span> &raquo;</a>';
			}
		echo '</div>';
	echo '</div>';

}