The base filters are the filters directly hardcoded on the ICP. They are manually updatable in the ICP settings:
HQ Location include/exclude (Multi Select)
Where the company should or should not have their headquarters
Founding date (Range)
When the company should have been founded
Headcount (Range)
How many employees the company should have
Yearly Estimated Revenue in $ (Range)
How much revenue in dollars the company should make per year. This data point is often estimated based on multiple attributes of the company