Hi Benjamin

Thanks for posting in Lucidchart Community! Unfortunately it's currently not possible to create a shape with only two rounded corners in Lucidchart. The rounded corner functionality applies to the whole shape. However we're always looking for ways to improve here at Lucid and your feedback is the best way for us to do that. Would you mind adding your idea to our feature request form? Ideas submitted to this form are passed on to the product development team for their consideration.

As a workaround you could upload an image of the shape and add it to your Custom Shapes library for easy access. For steps on how to do this please check out the Create custom shapes section of our Work with Shapes in Lucidchart Help Center article here.

Thanks for your request and I apologize for any inconvenience this causes you. Please let us know if you have any questions!