When you select a folder whose child folders are displayed as tabs, the first child folder is automatically opened. As a result, the child folders are never displayed in the Child Folders pane, where they need to be displayed for tasks like editing their Keyword Values.
To move up a level and display the child folder in the Child Folders pane, click the up-level tab available above the child folder tabs:
This tab is available when the current folder is configured to be displayed as a tab.