Can we make identifiers of the grid conditionally?

Could you clarify your question, maybe with an example?

When a row which has value A=0, then identifier should be B. Same when a row which has value B=0, then the identifier Should be A

A, B are the column in the cdt

Then yes, just set the identifiers attribute of the gridField something like:

identifiers: if(
local!cdt.A = 0,
local!cdt.B,
local!cdt.A
)

Apologies, just reread that - you're saying it's a row-by row identifier rather than the overall column. You can use an apply() of an if() function as above, but only if you're on 7.9 and above. If you're on an older version of appian, then you'll need to use a supporting rule and apply that rule with the two arrays as inputs.

The attached should help illustrate what I mean above. It looks like, even in the most recent Appian versions, you'll need a helper rule.

identifiers.txt

@dharsanag Added to philb's suggestion, adding a column to the data just for maintaining the identifiers and prepopulating the same conditionally, might simplify the things.