Cognos Cube Designer 10.2.2 Custom Relative Time Members

Hi All,
I have created N custom N-Period Running Total Definitions for 2019 and 2020 as
I will get
1. 2019 total if I drag 2019
2. 2019+2020(Cumulative) if i drag 2020.

Its all good so far..
 
But when I drag individual members for 2019(ie either M...