Hi JC
Thanks for your post and my apologies for the confusion. Just to be sure we're on the same page are you referring to the screenshot of the Actions menu in our Actions (Links and Hotspots) article? If so it looks like we've had some UI updates since the last time we updated our article. I'll pass this feedback on to our Help Content team so they can work to get that updated.
The Document link icon is now in the center and is used to link to a page in an existing Lucidchart document. To link to a Google Slides presentation you'll want to use the Link to Web option. You can paste the URL of your Google Slides where it says "Enter Web Link".
Let me know if you have anymore questions and I'm happy to help.