Multi line entry to SharePoint list from lookup Nintex control

I need to enter item from three instance of control to one sharepoint column. The control is a look up. When i tried to submit, nothing happned in sharepoint , it says null . I tried using JS, but it wouldn't work.Here is my sample JS code that i used. 

NWF.FormFiller.Events.RegisterAfterReady(function ()
{
NWF$('#' + ctrl_Egroup_One).on('change.onChangeEGroupOne', onChangeEGroupOne);
NWF$('#' + ctrl_Egroup_Two).on('change.onChangeEGroupTwo', onChangeEGroupTwo);
NWF$('#' + ctrl_Egroup_Three).on('change.onChangeEGroupThree', onChangeEGroupThree)
	
NWF$('#' + Suku_ID).on('change.onChangeFirstSelect', onChangeFirstSelect);
});

function onChangeEGroupOne(event) {
var arr=[];
NWF$(event.target).children('option').each(function(index, option){
		arr.push('#'+option.value);
	});
console.log(arr)
NWF$('#' + ctrl_Egroup_Two).val(arr);
NWF$('#' + ctrl_Egroup_Three).val(arr);

}

And Also here is one of three controls that i have used,