A pipe expression combines two expressions, separated by the | character. It is similar to a sub-expression with two
important distinctions:
- Any expression can be used on the right hand side. A sub-expression restricts the type of expression that can be used
on the right hand side.
- A pipe-expression stops projections on the left hand side from propagating to the right hand side. If the left
expression creates a projection, it does not apply to the right hand side.
https://jmespath.org/specification.html#pipe-expressions