Product Requirements Index Page (Or manually created by the Page Properties Report Macro (with label = requirements) has an ability to list the Product Requirements Pages within a Space. This is done by inserting the Space Keys in the second field, "Restrict to spaces".

What is suggested:
Be able to Restrict to Parent Page instead of Restricted to spaces.

Why:
Would be useful should there be several projects within one Space. For example:
Space A has the following Child Pages:

1. Project 1
   1. Project 1 version 1.1
   2. Project 1 version 1.2
2. Project 2
3. Project 3.

Let's say each version of Project 1 has a Product Requirement Page. Therefore, it would be nice if there is a Product Requirements Index Page within the page "Project 1", that would list all the product requirements pages which is restricted to Project 1 only.