Declaring nested parameters

Hello,

I am a beginner with SoapUI and after checking some responses from a few simple API methods I would like to try the same for more complicated methods which require some nested parameters like :

client => {
username => 'api client username',
password => 'api client password',
},
search => {
domain => 'mynewdomain',
extensions => [ '.co.uk', '.com' ]
}


So far I've worked only with "Method Parameters" tab but I don't know how to declare for example the variable "username" to be the child of the "client". Is there anyone who can give me a clue or some documentation that I should read in order to solve this?


Thank you!
Lucian