According to trinitarian theology, location has got nothing to do with whether God is God, or not. Nothing binds God or can command him. He created time, this universe, everything in it, and every location. That is why the Bible tells us that nobody can "get away from God", or hide from him, and that the Day of Judgment is coming when every person, great or small, dead or alive, will be caused to stand before God for judgment, when everything hidden will be revealed. All the 'Books' will be opened, wherein everything will be recorded.
I mention this as an introduction, because location has got nothing to do with the Being of God. The One who is God is not constrained or even affected by any location.
This simply means that, if the Son of God (being declared Son by his resurrection from the grave - Romans 1:1-4) IS God, then his location in heaven has no bearing on whether he is God, or not. He can be beside God because that is his rightful place, being God.
The rightful place of the Holy Spirit is also there, both surrounding the throne of God and being the seven eyes of the Lamb who is central (in position) on that throne, as described in Revelation 5:6-14. There are the three Persons of the Godhead central to the one throne of God in heaven. That is why the Revelation speaks of him being "in the midst of the throne", at the center of the throne of God in heaven, all heaven's creatures falling in worship before him who sits on the throne, and the Lamb (the risen Jesus Christ).
When Christ is depicted as sitting beside God on heaven's throne, he is not acting - he is not doing anything apart from waiting ("Sit at my right hand till I make your enemies a footstool for your feet" Psalm 110:1). When Christ is depicted as standing beside God at heaven's throne, he is paying particular attention to a particular something, on action-stations (as Stephen saw him just before he was stoned to death for addressing his prayer to the risen Christ - Acts 7:54-60). When Christ is standing in the middle of God's throne in heaven, where God also is, it is to open the sealed book and to receive heaven's adoration for that:
"And when he had taken the book, the four living creatures and the
four and twenty elders fell down before the Lamb... Thou are worthy to
take the book and to open the seals... Worthy is the Lamb that was
slain to receive power, and riches, and wisdom, and strength, and
honour, and glory, and blessing. And every creature... said [the same]
for ever and ever. And the four living creatures said, Amen. And the
four and twenty elders fell down and worshipped him that liveth for
ever and ever." (Revelation 5:9-14)
In addition, also read Revelation 3:1, 7:17 & 22:1-3. My first paragraph started with the point of the Day of Judgment coming when every person, great or small, dead or alive, will be caused to stand before God for judgment. It is the risen Christ they stand before, to be judged by him, as he told us in John 5:21-29. That makes perfect sense in light of trinitarian theology.