Will multiple h2 tags hurt my SEO?
The Frequently Bought Together widget title is set by default inside an <h2> HTML tag.
Urban legend says that having multiple <h2> tags is bad for SEO, but that is not true.
Multiple <h2> tags are perfectly correct following the HTML5 specification and will not negatively affect SEO.
You can see what Google says about repeating headers on its official YouTube channel:
Summarizing his words, it is normal to have repeated headers if they structure your store correctly.