If you’re using the Block Editor, you can use the “Query Loop” block or “Reusable Blocks” to include content from other posts or pages.

Creating & Inserting Reusable Blocks

1. Go to Posts or Pages and edit the content you want to reuse.
2. Select the block(s) you want to reuse, click the three dots, and select “Add to Reusable Blocks”.
3. Name the reusable block and save it.
4. For inserting the Reusable Block, edit the post or page where you want to display the content.
5. Add a “Reusable Block” and select the one you created.

Using Query Loop Block

1. Edit the post or page where you want to show content.
2. Click the “+” button to add a new block and select “Query Loop”.
3. Configure the block to display specific posts or pages.

The Insert Pages Plugin

The Insert Pages plugin for WordPress is a useful tool that allows you to embed the content of one page into another page or post. This is particularly helpful if you want to reuse content across multiple locations on your website without duplicating it.

1. Simply install and activate the plugin.
2. Upon activation, open the post, page, or any post type where you want to display content and click the ‘+’ icon.
3. Type ‘Insert Page’ in the search and insert the correct block.
4. Select the page you want to embed using the settings in the right-hand menu.
5. Under the ‘Insert Page’ option, either enter the URL of the page or begin typing its title, which will trigger a dropdown menu. From this menu, choose the appropriate page or post.
6. In the ‘Settings’ section you can view how the embedded content will look like.
7. From the ‘Display’ dropdown, select the type of content you want to include, such as the post title, link, excerpt, or the full page content.
8. The plugin also enables you to add custom CSS, opt to display the page content inline, and even restrict visibility to registered users only, hiding the content from anonymous visitors.
9. Once you’re satisfied with the appearance of the content, be sure to click ‘Update’ or ‘Publish’ to save your changes.

Alternatively, especially on old WordPress installations or sites using the classic WordPress editor, you can mirror content by using the Content Mirror plugin. The plugin enables you to mirror your WordPress site content from one page or post to another, you can also do this between subsites in a WordPress multisite network.

Simply install and activate Content Mirror. After activation, the plugin adds its TinyMCE button in the content visual editor, the button is simply used for mirroring content.

The plugin lets you mirror content from pages and posts, as well as custom post types and display it on other pages, posts, or custom post types. It is multisite compatible and works across sites in a WordPress multisite network configuration.