No, it’s not. A dimension requires freedom to be parameterized and independence from other dimensions. In this example “Y” is invariantly defined as 1. Similar

No, it’s not. A dimension requires freedom to be parameterized and independence from other dimensions. In this example “Y” is invariantly defined as 1. Similarly a level surface defines a dimension to a fixed value and provides an n-1 dimensional view of a n dimensional view. Mapping this to a level surface you declare Y=1 and only X is varying. Y has scale but no dimensionality due to its lack of freedom.