This is possible with the next coming release of MIGX (2.5.12) or with this mod:
https://github.com/Bruno17/MIGX/commit/7fed923f741a56b7cdf0166a4dec6224c3517021#diff-02f4fc20c3fb8a39c0a78fda75f1d1e2L199
Got the question how to parse nested json-strings with a snippet.
Here's the answer how to get this done with getImageList.
The outer getImageList:
[[getImageList?
&value=`[
{
"object":"house1",
"appartements": [
{"Obj_ID":"3A01",
"Etage":"EG"
},
{"Obj_ID":"3A02",
"Etage":"2.OG"
}
]
},
{
"object":"house2",
"appartements": [
{"Obj_ID":"3B01",
"Etage":"2.OG"
},
{"Obj_ID":"3B02",
"Etage":"1.OG"
}
]
}
]`
&placeholdersKeyField=``
&tpl=`houseTpl`
]]
the chunk 'houseTpl':
<h2>[[+object]]</h2>
Appartements:
<table>
[[getImageList?
&value=`[[+appartements]]`
&placeholdersKeyField=``
&tpl=`appartementTpl`
]]
</table>
the chunk 'appartementTpl':
<tr>
<td>[[+Obj_ID]]</td>
<td>[[+Etage]]</td>
</tr>
