How to pass nested json object through soapui in request api - json

Question

I am new to REST and i am making test cases for server client application. where server is made in php using symphony framework and clients are available both in android and ios. Server implements Rest instead of Soap. Now i have to make a test case in soapui to add a group in which nested JSON parameter is going but i am failed to send parameter as nested. I can show you the request from the log on server side.
[2014-09-24 11:14:36] las_api.INFO:
{
"request": {
"url": "http:\/\/192.168.1.134\/las_web\/web\/app_dev.php\/api\/users\/2\/groups.json",
"attributes": {
"_controller": "Las\\ApiBundle\\Controller\\User\\GroupController::cpostAction",
"_format": "json",
"userId": "2",
"_route": "api_post_user_groups",
"_route_params": {
"_format": "json",
"userId": "2"
}
},
"post": {
"group": {
"name": "Seniors"
},
"token": "{81A9B0D9-CA0E-E70F-ADFF-116EE7A1A980}"
},
"get": [
]
},
"ip": "192.168.1.134"
}
Below is the parameter request parameter. where in group there are two parameters first is name of the group and second is the token generated by server on login time.
{
"group": {
"name": "Seniors"
},
"token": "{81A9B0D9-CA0E-E70F-ADFF-116EE7A1A980}"
}
I have successfully made test case for login. I can show you the request from server log while logging.
[2014-09-24 10:11:37] las_api.INFO:
{
"request": {
"url": "http:\/\/192.168.1.134\/las_web\/web\/app_dev.php\/api\/tokens",
"attributes": {
"_controller": "Las\\ApiBundle\\Controller\\TokenController::cpostAction",
"_format": "json",
"_route": "api_post_tokens",
"_route_params": {
"_format": "json"
}
},
"post": {
"password": "abc123",
"username": "abc#gmail.com"
},
"get": [
]
},
"ip": "192.168.1.134"
}