I understand that Jesus was in the upper compartment of the Nether World/Hades/Sheol. Peter wrote, ". . .
he went and preached unto the spirits in prison; Which sometime were disobedient, when once the longsuffering of God waited in the days of Noah, while the ark was a preparing . . ." -- 1 Peter 3:19-20. And, ". . . the gospel preached also to them that are dead, that they might be judged according to men in the flesh, but live according to God in the spirit. . . ." -- 1 Peter 4:6, refering to the sons of God in Genesis 6:2 who died in the flood.
To answer the underlying OP question - "where was Jesus for those 3 days?"
Luke 23:
46 And when Jesus had cried with a loud voice, he said, Father, into thy hands I commend my spirit: and having said thus, he gave up the ghost.
John 7:33 Then Jesus said to them,[fn] “I shall be with you a little while longer, and
then I go to Him who sent Me. 34 You will seek Me and not find
Me, and where I am you cannot come.”
.......
19:30 So when Jesus had received the sour wine, He said, “It is finished!” And bowing His head, He gave up His spirit.
Jesus suffered the awful separation from his Father while on the cross. When he died he went to his Father in Paradise.
I don't think it profitable to discuss the geography of Heaven/Paradise. We will be with our Saviour in glory, awaiting the resurrection & the NH&NE.
We do need to consider those verses in 1 Peter 3:18-22 as they are readily misinterpreted.
18 For Christ also suffered once for sins, the just for the unjust, that He might bring us[fn] to God, being put to death in the flesh but made alive by the Spirit, 19 by whom also He went and preached to the spirits in prison, 20 who formerly were disobedient, when once the Divine longsuffering waited[fn] in the days of Noah, while the ark was being prepared, in which a few, that is, eight souls, were saved through water.
When did Jesus preach to the spirits in prison ? In the days of Noah. Note that Noah was a preacher of righteousness. 2 Peter 2:5 By the Spirit Jesus preached to the sinners of Noah's time.
Does 1 Peter 4 qualify this?
4 In regard to these, they think it strange that you do not run with them in the same flood of dissipation, speaking evil of you. 5 They will give an account to Him who is ready to judge the living and the dead. 6 For this reason the gospel was preached also to those who are dead, that they might be judged according to men in the flesh, but live according to God in the spirit.
Note the tenses - was preached ... are dead. The antediluvians heard the Gospel preached by & through Noah, rejected it & perished in the flood.
Peter is referring in 4:4 of those
who will harm you if you become followers of what is good. (3:13)
These verses are not some novel teaching about the afterlife but straightforward Gospel teaching. Hear the Gospel - repent & live; reject the Gospel & suffer fearful judgment. The dead do not escape judgment by dying! Nor do they have an opportunity to repent after death.
Jesus suffered on the cross, his spirit was received by his Father in Heaven/Paradise (as the dying criminal was, & we will) at death, and rose in triumph on the third day.