Hi there,
Today, you would need to nest a grid block inside each of those grid columns:
eg.
Grid Block
- Grid Column Container [1]
-- Grid Block
---- Grid Column Container [2]
------ Image Block
---- Grid Column Container [3]
------ Text Block
- Grid Column Container [1]
-- Grid Block
---- Grid Column Container [2]
------ Image Block
---- Grid Column Container [3]
------ Text Block
- Grid Column Container [1]
-- Grid Block
---- Grid Column Container [2]
------ Image Block
---- Grid Column Container [3]
------ Text Block
For Grid Column Container [1] you would set the Desktop width to 33% and Mobile to 100%
For Grid Column Container [2] & [3] you would set the Desktop width to 100%m and Mobile to 50%.