Multi level/hierarchical category axis chart

Hello, bihitakd0002
From here you can take reference and implement as per your requirement.

Thank you

{
a!columnChartField(
label: "Column Chart",
categories: {
"Category 1",
"Category 2",
"Category 3",
"Category 4",
"Category 5",
"Category 6",
"Category 7",
"Category 8"
},
series: {
a!chartSeries(label: "Chart Series", data: {1, 2, 3,4,5,6,7,8}),
a!chartSeries(label: "Chart Series", data: {1, 2, 3,4,5,6,7,8}),
a!chartSeries(label: "Chart Series", data: {1, 2, 3,4,5,6,7,8})
},
stacking: "NONE",
showLegend: true,
showTooltips: true,
labelPosition: "ABOVE",
colorScheme: "CLASSIC",
height: "MEDIUM",
xAxisStyle: "STANDARD",
yAxisStyle: "STANDARD"
)
}

No. This kind of label customization is not supported.

Appian doesn't support the layout as you've presented it. With a little thought you can achieve the same end. Options off the top of my head:

1. simply concatenate the labels on the chart as it is currently laid out e.g. 'Diagnostics/Other', 'Diagnostics/Pre-Anesthetic'
2. you could implement selectable drop-down or a drillable chart - where Level 1 of the chart shows the categories:  'Exams', 'Surgery', Vaccines' etc and by selecting/clicking on one of those top-level categories you reveal a second chart that shows the sub-categories