Hi Rach
Thanks for posting in the Lucidchart Community! Unfortunately it’s currently not possible to insert parts of your diagram into Google Sheet/Slide or into Microsoft Excel/PowerPoint – both our Google Add-on and our Microsoft Add-ins only allow for inserting pages of Lucidchart documents into a slide or spreadsheet.
However you can choose what portions of your diagram you’d like to put on a slide by using our presentation mode feature. This should allow you to transform your document into a slide deck presentation and then export it to Google Slides. To go over the details of how to turn parts of your diagram into a slideshow and send it to Google Slides please check out our Create a Presentation article from the Lucidchart Help Center.

Alternatively you can export portions of your diagram as images and then insert the resulting images into your spreadsheet or slide presentation. To do that navigate to File > Export > PNG/JPEG > Select “Custom Crop" from the download settings > drag from the corners and sides of the selection frame to surround the content you'd like to crop and download. To learn more about how to export your diagrams to different formats take a look at our Export/Download Your Lucidchart Documents article.

For those interested in learning more about how to insert your Lucidchart diagrams directly into your documents spreadsheets and presentations I’d recommend checking out our Lucidchart Add-on for Google Docs Sheets Slides and Gmail and Microsoft Integrations articles.
Hope this helps!