Projects expiring 3,6,9 months

[#1]

I have two fields 'Project_Name' and 'Project_Expiry'. How do I show projects expiring within the next 3, 6, and 9 months ?

Thanks in advance

[Digvijay_Singh]

In which chart you are using this, it works on text box, need to see where you are using it to understand the problem.

[#3]

I get an error in calculation. I believe this is because you can not use group functions directly in calculated dimension.

If I wanted to add this as an expression instead what should it look like ?