eg.json

{
   "profiles":[
      {
         "complex_modifications":{
            "rules":[
               {
                  "manipulators":[
                     {
                        "description":"Capslock to escape when used alone, to left control when used as modifier",
                        "from":{
                           "key_code":"caps_lock",
                           "modifiers":{
                              "optional":[
                                 "any"
                              ]
                           }
                        },
                        "to":[
                           {
                              "key_code":"left_control"
                           }
                        ],
                        "to_if_alone":[
                           {
                              "key_code":"escape",
                              "modifiers":{
                                 "optional":[
                                    "any"
                                 ]
                              }
                           }
                        ],
                        "type":"basic"
                     }
                  ]
               }
            ]
         }
      }
   ]
}