Sub-level tabs are secondary navigation elements within a user interface that reside under primary, or top-level, tabs. They allow users to access more detailed or specific sections related to the main category selected, facilitating a hierarchical organization of content.
For example, in a project management application, selecting a top-level tab labeled "Projects" might reveal sub-level tabs such as "Active Projects," "Archived Projects," and "Templates." This structure enables users to navigate directly to the desired subsection without excessive searching, enhancing the overall user experience. Implementing sub-level tabs requires careful design to maintain clarity and prevent overwhelming the user with too many navigation choices.