In Surah 56:7, three groups of people are mentioned; right hand people, left hand people and who are third group? Can you please be kind enough to explain regarding third group.

The third party is the special class of the first party, meaning that the first party has two degrees, they are the special class, and they are those who hurry to God Almighty, who do not delay in obedience, and the ordinary believer class. The two classes are in heaven, but the treatment of the special class is different from the treatment of the ordinary class, just as it is the case with those who travel in first class and those who travel in economy class, both on the same plane, but the advantages differ.