Saving checkbox values in editable grid

Hi Everyone,

I am facing an issue and I am not sure, What I am doing wrong.

Here is my datasubset 

{
{
record1: "21041001", 
nbr: "5DM874,C217668", 
recordname: {"test1", "test2"},
recordIds: {"75", "77"}, 
reportid: {}, 
selectedrecords: {}, 
selectedreports: {}, 
amount: 7.0,
recordamount: {15, 15}, 
reportamount: {}, 
trecordId: 76
},
{
{
record2: "21041100", 
nbr: "5DM874,C217668", 
recordname: {"test3", "test4"},
recordIds: {"78", "79"}, 
reportid: {}, 
selectedrecords: {}, 
selectedreports: {}, 
amount: 7.0,
recordamount: {15, 15}, 
reportamount: {}, 
trecordId: 88
}
}

I have an editable grid, which shows the record names in one of the column of grid from the above data subset and I ma trying to save the selected choices into "selectedrecords" parameter of above data subset using the following check box code.

a!checkboxField(
                    choiceLabels: fv!item.recordnames,
                    choiceValues: fv!item.recordnames,
                    value: fv!item.selectedrecords,
                    saveInto: {
                      fv!item.selectedrecords
                      
                    },
                    choiceLayout: "COMPACT"
)

I am getting the following error which is not helpful in understanding what I am doing wrong in saving the values to local variables.

Interface Definition: Expression evaluation error at function a!forEach [line 29]: Error in a!forEach() expression during iteration 1: Expression evaluation error at function a!checkboxField [line 53]: Incorrect number of parameters for function; expected 2 parameters, but found 3 parameters.