The Superhero Database Classification number, or SHDB Class, is a number that represents the overall 'power' of a character. All traits of a character are used for calculating the Classification.
What it DOESN'T mean
This doesn't mean that a higher class would always beat a lower class character. But the bigger the difference in Class is, the more obvious it is who'll win in a fight.
How is this calculated
( INT^1.3 + (STR*0.5 )^2 + (SPE*0.5)^2 + DUR^1.6 + (POW + (SPS*SPL))^2 + COM^1.8 ) ^ TIER
Super Power Score and Level
Every Super Power has a score (SPS) that is used to calculate the Class. Each Super Power also has 3 levels (SPL). The level is set when connecting that Super Power to a character. The level determines the final score, of the Super Power, being used in the calculation.
Haruka is the Ultimate Observer who transcends infinite dimensions / infinite timelines / infinite universes,
and even the Shangri-La dimension where Noein had ended / absorbed all universes into one.
Whatever Haruka doesn't observe, wouldn't even exist in the first place. Some similarities with concept of Azathoth, but not quite on that same Level.
But Haruka is still at least 1-A (Outer / OmniLock Level), possibly more, but there's not enough evidence in the series to also put her on Unity (High 1-A) and/or Boundless / Omnipotence (Tier 0).
Statements ~ Subtitles taken from the TV show which prove Infinite Dimensions
Link to a very instructive blog post which also puts Haruka at High 1-A