Referring to below link, the below upgrade currently allow "Get Items" to extract out a column with multiple people or groups but i think it works only for sharepoint online (if the source is sharepoint on premise, it does not work)
Currently, i am in midst of migrating from on premise to sharepoint online. but i think the current "Get Items" in power automate does not allow the program to extract out values when the column has multiple people and group. I have tested that for extraction from sharepoint online it works. but if source is from sharepoint on premise, the get items is not able to get the values. currently it will display as NULL. Kindly see below for my "Get Items" outputs when my source is from sharepoint on premise.