fix date months range selection

[gznster]

What I want 

What I created with the below query(i want to select the date ranges uniquely )

I'm trying to create something like this where can I click on the Tenure months and it'll query these ranges. I tried doing something like nested if else , but I'm kind of lost over here. 

If([TERMINATION_COMPLETION_DATE] - [TERMINATION_APPLICATION_DATE] >=0 AND [TERMINATION_COMPLETION_DATE] - [TERMINATION_APPLICATION_DATE] <=11, Dual('0-11',2),
If([TERMINATION_COMPLETION_DATE] - [TERMINATION_APPLICATION_DATE] >=12 AND [TERMINATION_COMPLETION_DATE] - [TERMINATION_APPLICATION_DATE] <=23, Dual('12-23', 2),
If([TERMINATION_COMPLETION_DATE] - [TERMINATION_APPLICATION_DATE] >=24 AND [TERMINATION_COMPLETION_DATE] - [TERMINATION_APPLICATION_DATE] <=35, Dual('24-35', 2), )))

If([TERMINATION_COMPLETION_DATE] - [TERMINATION_APPLICATION_DATE] >=0 AND [TERMINATION_COMPLETION_DATE] - [TERMINATION_APPLICATION_DATE] <=11, Dual('0-11',2),) OR
If([TERMINATION_COMPLETION_DATE] - [TERMINATION_APPLICATION_DATE] >=12 AND [TERMINATION_COMPLETION_DATE] - [TERMINATION_APPLICATION_DATE] <=23, Dual('12-23', 2),) OR
If([TERMINATION_COMPLETION_DATE] - [TERMINATION_APPLICATION_DATE] >=24 AND [TERMINATION_COMPLETION_DATE] - [TERMINATION_APPLICATION_DATE] <=35, Dual('24-35', 2), )