number number_type Comments
01         S          abc
01         F          cbd
02         A           xyz

"mappings": {
"test": {
"properties": {
"NUMBER" : {"type" : "integer"},
"HLOG_COMMENTS" :{
"type": "nested",
"properties" : {
"NUMBER_TYPE" : {"type" : "integer"},
"COMMENTS" : {"type" : "string"}
}
}
}

filter {
mutate {
rename => {"SEQUENCE_NUMBER" => "[HLOG_COMMENTS][SEQUENCE_NUMBER]" }
rename => {"USERID" => "[HLOG_COMMENTS][USERID]" }