How do I create functions?

Hello! I got a warning about screen limits in the App Inventor and I'm now trying to create a single screen.

How can I create a function for each group of blocks in the screenshots?

I want to make a function for each group and then call one of them to fill the list in the screen.

See the YAML_Elments value procedure in

Also, study up on procedure parameters, and how they make procedures reusable.