innerId

returns the inner ID of an item by its public (real) ID

The method will be to the point when you use the same IDs for several nested components, e.g. you place two columns on a page and put a list component inside each of them.

Both lists have the same ID:"mylist".

webix.ui({
   cols:[
     { id:"col1", isolate:true, rows:[
        { view:"list", id:"mylist", data:webix.copy(list_data)  },        
     ]},
     { id:"col2", isolate:true, rows:[
        {view:"list", id:"mylist", data:webix.copy(list_data) },        
     ]}
   ]
});

So, when you need to refer to one of these lists, you should use:

// for example, to get the id of the list in the second column
$$("col2").innerId("$list2");

Vice versa, to get the real ID of an item, use the code as in:

var realId = some.$$(innerId).config.id