To me, the deity of Christ is seen all throughout Revelation, and for that matter, the Gospels (e.g. John 1:1) and Epistles, and all of Scripture, but for the purposes of the question, how do those who do not believe in the deity of Christ ('that Jesus is God in the flesh') view such passages as Revelation 2:23?
Revelation 2:18,20-23 ... These things says the Son of God, whose eyes are like a flame of fire, and whose feet are like refined bronze1 ... But I have this against you [i.e. the congregation at Thyatira]: that you put up with that woman Jezebel, who calls herself a prophetess, and teaches [falsely], and misleads my servants, seducing them into sexual promiscuity and the eating of things sacrifices to idols. And I have given her time that she might repent, but she was unwilling to repent of her sexual sin. Behold, I will cast her onto a bed of sickness, and those that commit adultery with her into great affliction, if they do not repent of their deeds. And her children I will strike with death; then will all the churches know that I am he who searches the minds and the hearts, and [that] I render to each of you according to your works.
In light of this being the perogative of YHVH, God Almighty:
Jeremiah 17:10 I, YHVH, search the heart and examine the mind, to render to each according to his conduct—according to the fruit of his doings.2
IMPORTANT EDIT
As noted by another user 2 Chronicles 6:30 (cf. 1 Kings 8:39) teaches explicitly that YHVH alone knows the hearts of men:
1 Chronicles 6:14, 30 O YHVH, God of Israel, ... So then, hear from heaven, your dwelling place, and forgive, and render to each one according to all his ways, [you] who know his heart: for you alone know the hearts of the sons of men.
Footnotes
1 Fresh translations throughout for reasons of consistency; largely irrelevant for the purposese of the question. | cf. 1:10-18; 2:8
2 cf. Jer 11:20; 20:12; Wis 1:6-7; Rom 8:27
3 cf. Nahum 1:3; Rev 3:19; Prov 3:12; Heb 12:6