The data reported by Google in the Search Analytics section in Search Console is aggregated for the entire set of results corresponding to a query (organic links, Google Maps section, featured snippet box (rich answer box)). If you’re looking at impressions per query, impressions per pages per query, you have to take into account the data you see refers for the whole set of results. So, when you have multiple pages ranking independently for the same keyword in search then Google picks one of those pages (the top ranking one) and counts that one as impression, also uses that top ranking page for calculating the average position for that query.
When this happens you get an image of how your website performs on Google on a specific query, helping you understand how much visibility you have with your top ranking only, not per page or each instance.
Example 1: on Google’s 1st page the link to your website is within the Google Maps section above all the organic links, and you also have an organic link to one of your website’s internal pages. It will count as one impression for that query and for your homepage (linked from the Google Maps section), it will also be considered position 1 on Google (already said Google Maps section above all organic links) when calculating the average position for that query and your homepage. Your internal page won’t be reported in Search Analytics.
Example 2: considering a query such as ‘dental implant’ and your website ranking with your internal page example.com/dental-implant on position 2 and your homepage on position 3, Google will add one impression to internal page example.com/dental-implant and use position 2 when calculating the average position for that query for the determined period of time. Your homepage won’t be reported in Search Analytics.
Example 3: considering a query such as ‘handyman in Richmond’ and your website ranking on position 1 with an internal page example.com/services/handyman and within the Google Maps section (between organic positions 1 and 3) linking to your homepage, Google will add an impression to that query and the internal page example.com/services/handyman and will also use position 1 when calculating the average position for that query and your internal page. Your homepage won’t be reported in Search Analytics.