There are billions of Brahmanda universes all originating from the Body of Maha Vishnu. Inside each Brahmanda universe, is a secondary smaller universe where Garbhodakashayi Vishnu, Lord Brahma and all the different Planetary Systems are found. This inner material universe, is surrounded and encased by the outer Brahmanda universe's 7 massive material layers.

These are the names of the 14 material planetary Systems below in photo, just in our single material universe which is situated deep within our surrounding massive Brahmanda.

There are billions of these Brahmanda universes, all coming from the Body of Maha Vishnu as seen in painting below.

Each Brahmanda has their own "secondary inner material universe" deep inside their surrounding Brahmanda universe.

And each inner  secondary universe has their own Planetary System, that are all in different sizes, ours has 14 different Planetary Systems.

This means there are billions of Garbhodakashayi Vishnus, billions of Lord Brahmas, billions of Lord Shivas, billions of Indrus, billions of all the demigods in each universe deep inside their outer Brahmanda greater universe, but only ONE Maha Vishnu, as seen in painting below.