Sharing a manual will enable you to share content between sites at the manual level. By following these procedures, you can create content in a manual, share it between sites, and when you make updates to the manual in one site, the changes will be reflected in each site the manual has been shared to.
Select Add Existing Manual from the Category action menu
Click the action menu to the right of a Category.

Select Manual > click Add Manual
Select the manual you would like to add from the Manual menu then click Add Manual. The manual will be added to your site.

The manual will have an icon next to signifying that the manual is shared (or referenced) in multiple sites. Editing the manual in one location will edit the manual in every site it appears in.

See which sites it appears in
Hover your mouse over the blue dot to view which sites the manual appears in.

Is there a way to share specific articles between sites?