How to Print Multiple Documents
If you use File > Print in DEVONthink, it will print what is shown in the selected pane. For example, if you have the groups list selected, it will print the groups as displayed; if you select a document, it will print the contents of the document. However, you cannot select multiple documents and print them — but this old trick still works well:
Open System Preferences > Printers & Scanners to view your installed printers. Drag the desired printer from the device list to your Dock. You can now drop files to this icon to print them. And this doesn't only work for documents in DEVONthink, it works in the Finder too (though it may launch an application to print).
Note: If you need custom settings, like a range of pages or scaling, you'll need to print the documents individually. This method uses the default settings for all dropped files.