Joining two or more tables at Interface level

Hi Digantas,
Hope I got your requirement, We can achieve this by constructing a Temporary CDT rule, In that rule you need to configure the variable you need.
Consider
CDT 1 having A1, A2, A3, A4,C
CDT 2 having B1, B2, B3, B4,C
As per your requirement, will construct a Temporary CDT rule and pass CDT1 and CDT2 as parameter. Finally store the value in a local! variable. Then make use of it in a paging grid.
{
C:C
C1:A1,
C2:A2,
C3:B1,
C4:B4
}

Hi Digantas,
Hope I got your requirement, We can achieve this by constructing a Temporary CDT rule, In that rule you need to configure the variable you need.
Consider
CDT 1 having A1, A2, A3, A4,C
CDT 2 having B1, B2, B3, B4,C
As per your requirement, will construct a Temporary CDT rule and pass CDT1 and CDT2 as parameter. Finally store the value in a local! variable. Then make use of it in a paging grid.
{
C:C
C1:A1,
C2:A2,
C3:B1,
C4:B4
}

the field "C" from cdt1 differs field C of CDT2
tried using Union/intersection function to eliminate duplicacy, but gave an array
cannot index data of list of Variant. Need Scalar values

Out of my curiosity, can you explain me with an example
What I get from this is,the values will be like
In CDT 1,C field having 1,2,3
In CDT 2,C field having 2,4,5.
If my understanding is correct, then let me know that the duplicate column are having same row values or not?

I need to create a temporary cdt by intersecting these 2 cdts so that I can get only values corrsponds to '2'.

I think you need to give us small fragments of sample data as an example of what you'd get for data set A, data set B, and what you'd expect the merged set C to look like (and maybe a short explanation of why, if it's not obvious). That is unless dhivyam 's prior suggestion was sufficient.