In order to assign team members to a folder, first select the "Folders" subheading in the left-hand sidebar to bring up your list of folders.

Next, click on the horizontal three-dot "Actions" button on the left-hand side of your desired folder to select the "Edit folder" button.

This will open a window where you can edit the name of the folder and use the "Default Assign To" drop-down list to assign the folder to specific team members. once you have made your changes, click the "Save" button in the top right-hand corner.