Start with four pinned spend values. Two of them sit on the important edges: 30 starts the medium band, and 70 starts the high band.
Use the rules row by row. The original spend column stays numeric, and the new spend_band column is a label you can group or filter later.
Turning a numeric column into an exact low, medium, or high band with pinned boundary rules.
highlighted = computed this step
Input numeric column
Start with 4 pinned spend values.
numeric input
Exact band rules
Use exact boundaries: medium starts at 30, and high starts at 70.