How To Filter By Category?

I apologize upfront if this is a basic/silly question, but I don’t knwo the answer, so I’m asking . . .

So I have several video section blocks … each with a row of videos set to each respective category. HOW do I filter the videos displayed for each block by category?

Is it a particular url link I set?

I tried looking throughout the documentation but I couldn’t find the answer.

Thank You