How to get difference between 2 custom fields

[Sanjivani Wayal]

Hi

I want to get difference between 2 custom fields both are multiuser pickers and want to add this difference in another multiuser field . i have written {{issue.app1.displayName}} - {{issue.app2.displayName}} taken it in variable diff and then added and action to edit the 3rd field (app3) by SET {{variable}} but this is removing all the values from 3rd field.

Also tried below -

{
"update": {
"app3": [
{"remove" : {"name": "{{issue.app2}}"}}
]
}
}

Still doesnt work 

[Sanjivani Wayal · Accepted solution]

I found the code for the same 

{
"update": {
"app3": [
{{#issue.app2}}{"remove": {"id":"{{accountId}}"}}{{^last}},{{/}}{{/}}
]
}
}

it worked for me