You can see the top engaged people (people who posted, commented or reacted) on your interface (Members metrics).
To get the full list of people, you can export the list of members in Members metrics > Members list. Then, you can remove people with a score of 0 to get the number of people who generate any engagement.
Sentiment score : percent of positive publications + percent of neutral publications.
Percent of positive publications : (number of positive publications * 100)/ number of publications analyzed.
Percent of negative publications : (number of negative publications * 100)/ number of publications analyzed.
Percent of neutral publications : (number of neutral publications * 100)/ number of publications analyzed.
Percent of mixed publications : (number of mixed publications * 100)/ number of publications analyzed.