To have a Published Form not be displayed as a category within a Tab/Parent category (for cases when users want to use the direct link of the Published Saved Search instead ) then follow these steps:
1. Navigate to List > Web Site > Tabs > New > select Presentation Tab. Fill in mandatory fields and save.
2. Navigate to Lists > Web Site > Published Forms > New or edit existing record. If new select the type of form. Set all mandatory fields and set the site Site and Site Category fields for one row to be the Tab created in Step 1 and save.
3. Go to the web store and get the URL for the published form by going to the tab from step 1. Copy this URL for later use.
4. Navigate to List > Web Site > Tabs. Edit the tab from step 1. Un-check Display in Web Site and Save.