Are there features that actually specify their own bonus action timing?

The PHB States:

You choose when to take a bonus action during your turn, unless the bonus action’s timing is specified, and anything that deprives you of your ability to take actions also prevents you from taking a bonus action.

I’ve found lots of triggering specifics, but nothing that says WHEN you have to take it.

Are there example(s) where the exact timing of the bonus action is dictated and not just the triggering requirement FOR a bonus action that you then choose when or if to use.