How can I exclude a current user from the selection from the workflow?

[Wilco Broersen]

How can I exclude a current user from the selection from the workflow? 

{
"name": "Job Expert",
"transitions": {
"rejected": "Editor",
"approved": "Process Owner"
},
"colour": "#00B8D9",
"approvals": [
{
"name": "Job Expert",
"preassignedUsers": {
"items": [
"60a245b1b050a700690a1d2f"
]
},
"preassignedGroups": {
"items": [
"c6d0fa87-a016-4c93-b338-cfdf8346463f",
"167fc8cd-e061-47f5-9028-730bb36db918"
]|
},
"minimum": 1,
"assignable": true
}
]
}

[Wilco Broersen]

And is it possible not to send it to preassignedGroups but let them select one person of that group?