Objective idealism shares some traits with materialism, as in that framework primary spirit/essence produces material world, which is then interactable by subjective spirits/consciousness

We can discover it and search for commonalities. We can’t grasp totality of something like a table. You see a table, you can perceive and conceptualize a table, but what exactly is table color objectively? Unless you enter realms of science, you can’t objectively describe a table. Description such as “it’s light-brown” is subjective, what is table uv color? How does it look on nanoscale? What is table composition chemically? Those are objective description of material reality. Subjectivity can find material reality (which is exactly what science is, and why it came from philosophy, especially physics) through search of objective.

You, a single human, can’t find natural law of physics, but finding a law and then receiving it confirmation from independent source means it is likelier to be objective description of material world