Help creating tabular matrix view in Deneb

I am trying to create this custom gantt chart visual with Deneb. I would like to add a parent column and would like it to replicate the tabular format of a matrix. I am able to create the new column using calculate to create parent subgroups but need help to only show the first value in my parent subgroup in Deneb. Thank you so much for your help in advance!!

This is what I current have in Deneb: 

This is what I would like to replicate in Deneb: 

Deneb Code 

{
 "data": {"name": "dataset"},
 "spacing": 12,
 "transform": [
 {
 "calculate": "datum['Sort Order'] === 1 || datum['Sort Order'] === 2 || datum['Sort Order'] === 3 ? 'Fruit' : null",
 "as": "Parent1"
},
{
 "calculate": "datum['Sort Order'] === 4 || datum['Sort Order'] === 5 || datum['Sort Order'] === 6 ? 'Vegetables' : null",
 "as": "Parent2"
},
 {
 "calculate": "datum.Parent1 || datum.Parent2",
 "as": "Parent"
 },
 {
 "window": [
  {"op": "first_value", "field": "Parent", "as": "Parent Test"}
],
 "frame": [null, null],
 "groupby": ["Parent"]
 },
 {
 "filter": "datum['Parent Test'] !== null"
 }
],
 "hconcat": [
 {
"mark": {"type": "text"},
"encoding": {
 "y": {
 "field": "Level 2",
 "type": "ordinal",
"axis": null,
 "sort": {
 "field": "Sort Order",
"order": "ascending"
 }
},
"text": {
   "field": "Parent Test"}
 }
 },
 { "mark": {"type": "text"},
 "encoding": {
 "y": {
 "field": "Level 2",
"type": "ordinal",
"axis": null,
 "sort": {
 "field": "Sort Order",
"order": "ascending" }
 },
 "text": {
 "field": "Level 2",
 "type": "nominal"
 }
 } }
]
}

my data table since I can't seem to attach a file 

Level 2Sort OrderLevel 1