1. Switch the article to the outline view, find the chapter titles of the article respectively, click the small triangle on the right side of the outline level selection box on the outline toolbar, and select "1 level" and "level 2".

2. After defining the title, switch to page view and insert the table of contents: click the area where you want to insert the table of contents, and then click Insert-Reference-Index and Table of Contents in the menu bar to open the index and table of contents dialog box, where you can set the display format of the table of contents, and finally click OK to generate the table of contents.