Does the worshiper receive the reward for congregational prayer in the mosque if he prays Asr in a congregation at his workplace's prayer room, where their number does not exceed four?

If you performed the 'Asr prayer in your workplace prayer room and one or more individuals prayed with you, then you and the others have, God willing, attained the reward of congregational prayer. However, it is better to perform the prayer in a congregational mosque, due to the saying of the Prophet, peace and blessings be upon him: "A man's prayer with another man is purer than his prayer alone, and a man's prayer with two men is purer than his prayer with one man, and the more numerous they are, the more beloved it is to Allah the Almighty."