Variable End dates for DATESBETWEEN function

Hi amitchandak 

Thanks for your quick replies! 

Yes Today() function is together with a measure that uses SELECTEDVALUE

to further break it down: That Selected Value is below:

Week Variable =
var _select = SELECTEDVALUE('Calendar Week Look Ahead'[Weeks])
return
SWITCH(
TRUE(),
_select="1 Week",7,
_select="2 Weeks",14,
_select="3 Weeks",21,
_select="4 Weeks",28,
_select="5 Weeks",35

)

As you can see my intention here is the Have a slicer that controls the Dates Range. TODAY() function works well as a measure together with SELECTED VALUE measure. It becomes a different story when it is inside the DATESBETWEEN. 

I recreated a similar powerbi with same issue. 

https://drive.google.com/file/d/1yYBADrkbG--5cl-dix3gLaFfY6A-_bPm/view?usp=drive_link

Here are the measure that works (Table or Card Visual:

Does this mean SELECTEDVALUE cannot be used for DATESBETWEEN if SELECTEDVALUE is picking up from a column or table?

Thanks again