The guide of Google Follow the structured data guidelines tells us:
Important: Google does not guarantee that your structured data will
show up in search results, even if your page is marked up correctly
according to the Structured Data Testing Tool. Here are some common
reasons why:
...The structured data is not representative of the main content of
the page, or is potentially misleading.
and further:
Relevance
Your structured data should be a true representation of the
page content.
Thus your structured data should represent the main content of a web page to which they refer. If your home page has main content such as the presentation of your business, then the structured data must be of the top level type (main type). one that represents your business, for example, the type LocalBusiness or some more specific of the type LocalBusiness.
If your business has a subject such as a product, then you can use the following properties for the embedded product:
- hasOfferCatalog with the embedded type OfferCatalog
- makesOffer with the embedded type Offer
You can also use the property mainEntityOfPage and in its value specify the URL for the web page representing your product.