Extend Condition Builder Example

[olsp]

I would like to have the possibility to use check how many assets a field has assigned. As far as I understand from the docs, this should be possible with the Condition Builder Framework. The docs about this aren't very helpful for someone like me, I don't really know where to start to implement this. Are there any examples, resources or something similiar I could look into, to start learning about this?

I have created custom modules (with generator) before, I guess this would be the starting point. But from there on I would like to learn how to implement this feature.