ESQL: a nested field having the same name as a supported one discards the supported field name

[astefan]

Description

For this mapping

{
    "mappings": {
      "properties": {
        "Responses": {
          "properties": {
            "process": {
              "type": "nested",
              "properties": {
                "pid": {
                  "type": "long"
                }
              }
            }
          }
        },        
        "process": {
          "properties": {
            "parent": {
              "properties": {
                "command_line": {
                  "type": "wildcard",
                  "fields": {
                    "text": {
                      "type": "text"
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
}

and query that is using process.parent.command_line - from test | sort process.parent.command_line or from test | where process.parent.command_line == "test string" results in Unknown column [process.parent.command_line] which is incorrect.

[elasticsearchmachine]

Pinging @elastic/es-analytical-engine (Team:Analytics)