The 4th is destroyed before the 3 first kingdoms are allowed to continue so they are not under the 4th kingdom at all. There is nothing about the 4th kingdom continuing in any form at all. That's added to the text by those who think it was Rome, and how the RCC was in power after but none of that matches the text by Daniel. People want it to have been Rome sop badly, they literally force it all into the text.
Dan 7:9 I beheld till the thrones were cast down, and the Ancient of days did sit, whose garment was white as snow, and the hair of his head like the pure wool: his throne was like the fiery flame, and his wheels as burning fire.
Dan 7:10 A fiery stream issued and came forth from before him: thousand thousands ministered unto him, and ten thousand times ten thousand stood before him: the judgment was set, and the books were opened.
Dan 7:11 I beheld then because of the voice of the great words which the horn spake: I beheld even till the beast was slain, and his body destroyed, and given to the burning flame.
Dan 7:12 As concerning the rest of the beasts, they had their dominion taken away: yet their lives were prolonged for a season and time.
Dominion not taken away until after the 4th is gone.
Just as it is written.