Planning is the activity where you decide your testing strategy (e.g.  which requirements you want to validate, how to validate them, use either manual or automated tests), the resource allocation, and the execution plan (whom and when will execute the tests). Depending on several factors, you may want to prioritize some of the tests, or give more focus on some requirements. 

Although you may plan tests in different ways, Xray v2 introduced the Test Plan issue specifically for this purpose and we do recommend you to use it.

Inside your Test Plan you can put the Tests you want to track for a given version and the Test Plan will show you the consolidated results for those Tests; in other words, it will present the latest status for each Test, independently of the number of testing iterations (i.e. Test Execution) you make with them.

Xray v3.0 gives you the option to use hierarchical test organization, which you may also take advantage at Test Plan level by using the Test Plan Board. In Overview of the Test Plan Board - TO DO you may better understand how it extends the existing Test Plan concept adding to it the ability of organizing Test Plan's Tests within folders.