Dynamic Y-axis max on a shared line chart (measure switch + field parameter).

Anonymous 
Thank you for the detailed response.

Your suggested approach would work well if my Y-axis scaling were controlled only by the Revenue, Cost, and Cost % measures.
However, in my case, the scaling is also influenced by a Calendar field parameter that dynamically changes the X-axis grain (D, W, M, Q, Y).

• Selecting D switches the X-axis to Day level

• Selecting W switches it to Week level, and so on

Here’s where the challenge arises:
I have four KPIs — Sales Score, Total Sales, Total Profit, and Profit %.

• For Sales Score and Profit %, I need to set a fixed Y-axis range (100 and 100% respectively).

• For Total Sales and Total Profit, Power BI’s auto-scaling works well and should remain as-is.

The difficulty is that when I fix a manual range for metrics like Total Sales, the visual looks incorrect because the scale should vary by time grain (Year > Quarter > Month > Week > Day).

I considered writing a DAX formula to dynamically determine the Y-axis max, but I need a reliable way to capture the state of the field parameter (which represents the selected time grain).
Unfortunately, using SELECTEDVALUE() on the field parameter’s [Field] column throws a composite key error.

I’m trying to find the best practice for:

1. Detecting which field parameter option (D/W/M/Q/Y) is currently selected.

2. Using that selection along with the chosen KPI to calculate a dynamic Y-axis max that mixes both fixed and auto-scaled behaviors.