WordPress already makes it easy to import or export data to/from your site. We have also covered a bunch of plugins that give you more flexibility exporting your data. Plugins such as Single Post Exporter can save you even more time. It lets you select which posts to export.
Single Post Exporter lets you export single or multiple posts, pages, and custom posts with one click. You can export posts while viewing all posts or editing individual pages. Importing what you have exported is also straightforward.
You can try this plugin for free.