Hi there! If you change your mind and want to unshare a folder simply click the “Share” button click “Advanced" and then click the “X” to remove the collaborator. You can also adjust your collaborator’s editing permissions here.

there is NO advanced button.  How to remove access from a shared folder

Hey Nancy

Thank you for keeping this conversation going! If you are looking at the Lucid homepage lucid.app you will click on Documents. From there find the folder that you wish to remove collaborators from and click "Share" or the grey silhouette. There will be a pop-up menu that you can then select "manage" on the bottom-right of. This will be the screen that you can use to remove the collaborators.

Hope this helps--please let me know if you have any questions or trouble. Cheers!