You can create a custom layout template from a page you have already designed in Beaver Builder (including a Themer layout), or you can create a layout template from scratch starting from the Beaver Builder admin panel.
If you want to use a layout from one page to create another within your site, you can duplicate the page rather than saving a layout template. Duplication creates a copy of your current page, including metadata.
To save an existing page in Beaver Builder as a custom layout template:
On the Tools menu, click Save template.
The Tools menu is in the upper left corner of your screen. You can access it by clicking the down arrow in the title bar.
Give the template a name and click Save.
To create a new custom layout template from the Beaver Builder admin panel:
In the WordPress admin panel, go to Beaver Builder > Templates.
If you don't see Beaver Builder in the admin panel, see this article on enabling it.
Click the Add new button next to the page title Templates.
Enter a title for the template and click Add saved template.
Click Launch Beaver Builder and construct the layout.
To save the layout template, click Done > Publish.
Layout templates are not public pages on your site and are not available for indexing by search engines.
See the this article for information about working with saved templates.