Replace tab value inside formula with cell value

[Haywire]

Hi all,

It would be extremely helpful if anybody can help me with this problem, which again would be obvious but for the life of me can not figure it out. I also tried searching the Forum but an error with "run out of memory" occurs, sorry if this has been asked before.

I need to replace or substitute a tab reference value inside a formula to display the value of the cell in the validation drop down list. I have attached a file to explain the situation better.

Please help!
Thanks