collapse macro - question. How can I use sub-collapse, for example collapse in collapse - Redmine

collapse macro - question. How can I use sub-collapse, for example collapse in collapse

I'll try to ask my question easiest way based on example.
I need 3 levels of collapse, but, unfortunately it works only for 1 level.. :(

{{collapse(First Parent Collapse)
Parent
{{collapse(2nd child Collapse)
Child
{{collapse(3rd sub-child collapse)
Sub-Child
}}
}}
}}

}}
}}

I try to google solution in redmine.org or anywhere else, but didn't find..

Thanks in advance for any help!