Kode dari artikel https://solusipress.com/menampilkan-listing-artikel-2-kolom-pada-tema-generatepress/

functions.php

<?php

/* Display 2 columns post archive in GeneratePress theme */
class SolusiPress_Post_Grid {
	
	protected $post_count = 0;
	protected $valid_area = false;
	
	public function __construct() {
		add_action( 'wp_head', array( $this, 'custom_css' ) );
		add_filter( 'post_class', array( $this, 'two_columns' ), 10, 3 );	
		add_action( 'get_template_part', array( $this, 'before_template'), 10, 3 );
		add_filter( 'the_content', array( $this, 'remove_content' ) );
		add_action( 'generate_after_loop', array( $this, 'add_clearfix' ) );
	}
	
	private function check_page() {
		return ( is_home() || is_archive() ) && get_post_type($post_id) == 'post';
	}
	
	public function custom_css() {
		if( $this->check_page() ) {
			echo '<style type="text/css"> .grid-no-content .entry-content { display:none; } </style>';
		}
	}
	
	public function two_columns( $classes, $class, $post_id ) {
		if( $this->check_page() && $this->valid_area ) {
 			$this->post_count++;
			$classes[] = "grid-50";
			$classes[] = "grid-no-content";
		}
		$this->valid_area = false;
		return $classes;
	}
	
	public function before_template( $slug, $name, $templates ) {
		if( $slug == 'content' ) {
			$this->valid_area = true;
			if( $this->post_count % 2 == 0 ) {
				$this->add_clearfix();
			}
		}
	}
	
	public function remove_content( $content ) {
		if( $this->post_count > 0 ) {
			$content = '';
		}
		return $content;
	}

	public function add_clearfix() {
		if( $this->post_count > 0 ) {
			echo '<div class="clearfix"></div>';
		}
	}
	
}
new SolusiPress_Post_Grid();