You can repost existing posts that have been published, scheduled or saved to the same page or other pages in the workspace.
To do so, just click on the post menu and find the Repost option. When clicking it, the composer will open with the content from the post you selected.
From the composer you might want to slightly modify the post, duplicate it to another page or publish/schedule it again for later.
You can also copy the post to another workspace.
If you want to duplicate several posts at once to other pages or workspaces, you can do that from the list view.
Select list view, select posts, and then select "Copy to other pages or workspaces". Afterwards, find the page / workspace you want the posts to be duplicated to.