Even though i am copying the field name from the remote replica ,still its showing Null value.

Below is the remote replica 

 "Functional Area – PCM": {
        "id": 15205,
        "name": "Functional Area - PCM",
        "uid": "15205",
        "type": "OPTION",
        "value": {
          "id": "22009",
          "sequence": 6,
          "value": "PCM",
          "disabled": false,
          "childOptions": []
        }
      }
    },

SANDEEP ADE 

What is the error thrown?

I am getting "Cannot get property 'value' on null object"

But in the remote replica i am seeing the below

 "Functional Area – PCM": {
        "id": 15205,
        "name": "Functional Area - PCM",
        "uid": "15205",
        "type": "OPTION",
        "value": {
          "id": "22009",
          "sequence": 6,
          "value": "PCM",
          "disabled": false,
          "childOptions": []
        }
      }
    },

I tried the below options but both are throwing error

defect.customFields."BG_USER_02".value = replica.customFields."Functional Area - PCM".value.value

defect.customFields."BG_USER_02".value = replica.customFields."Functional Area - PCM".value(0).value 

Can it be that defect.customFields."BG_USER_02" is null?

i didn't quite get what you said 

BG_USER_02 is a field in ALM ,i am trying to populate the value "PCM" received from Functional Area – PCM from JIRA in BG_USER_02 which is ALM.

i have the code as  below,

JIRA SENDING SIDE

replica.customFields."Functional Area – PCM”= issue.customFields."Functional Area - PCM"

ALM INCOMING SIDE

 defect.customFields."BG_USER_02".value = replica.customFields."Functional Area - PCM".value.value

and to confirm Functional Area - PCM is not Null because in the remote replica i am seeing value as PCM for this field

So not sure whats the issue

It can still be that the nullpointerexception is raised by

 defect.customFields."BG_USER_02".value

So the question - can you check what defect.customFields."BG_USER_02" returns when doing

debug.error("defect.customFields.BG_USER_02 = ${defect.customFields."BG_USER_02".properties}")

javax.script.ScriptException: com.exalate.api.exception.IssueTrackerException: defect.customFields.BG_USER_02 = [value:null, type:STRING, class:class com.exalate.basic.domain.hubobject.v1.BasicHubCustomField, uid:BG_USER_02, id:null, locked:false, description:null, name:null]

i got this error

Also i added below line

def remoteValue = replica.customFields."Functional Area - PCM".value.value to see the value on incoming remote field ,it gave error as Cannot get property 'value' on null object

but i see the value in remote replica 

  "Functional Area – PCM": {
        "id": 15205,
        "name": "Functional Area - PCM",
        "uid": "15205",
        "type": "OPTION",
        "value": {
          "id": "22009",
          "sequence": 6,
          "value": "PCM",
          "disabled": false,
          "childOptions": []
        }
      }

its resolved now

issue was the "-" symbol ,the field name is Functional Area - PCM 

and in script it was types as Functional Area – PCM