Summarize table Lookupvalue in Funnel Visual

It sounds like you're running into an issue with the granularity of your calculations after adding the Quarter and Month filters to your summarized table. The problem you're facing is that the DAX formula is calculating the percentage growth for each row and then summing them up, instead of calculating the percentage growth for the entire selected dataset.

To fix this, you need to adjust the way you're using the LOOKUPVALUE function. When you're using LOOKUPVALUE, it's trying to fetch a single value based on the criteria you've provided. But when you have multiple months or quarters selected, it's not going to fetch the correct value for the entire selection.

Instead of using a calculated column for the PercentageYearlyGrowthByCoverType, you should use a measure. Measures are designed to work with aggregated data, which is what you want.

Here's a suggestion for the measure:

PercentageYearlyGrowthByCoverType Measure =
VAR CurrentYearPremium = SUM(CoverTypeAnalysis[Total Premium])
VAR LastYearPremium =
CALCULATE(
SUM(CoverTypeAnalysis[Total Premium]),
FILTER(
ALL(CoverTypeAnalysis),
CoverTypeAnalysis[Transaction Year] = SELECTEDVALUE(CoverTypeAnalysis[LastYear]) &&
CoverTypeAnalysis[Transaction Quarter] = SELECTEDVALUE(CoverTypeAnalysis[Transaction Quarter]) &&
CoverTypeAnalysis[Transaction Month] = SELECTEDVALUE(CoverTypeAnalysis[Transaction Month]) &&
CoverTypeAnalysis[Cover Type] = SELECTEDVALUE(CoverTypeAnalysis[Cover Type])
)
)
RETURN
DIVIDE(
CurrentYearPremium - LastYearPremium,
ABS(LastYearPremium)
) / 100
This measure first calculates the total premium for the current year and then calculates the total premium for the last year based on the selected values in your slicers. The FILTER function with the ALL function ensures that the entire table is considered, and then it filters down to the values based on the slicers. Finally, the DIVIDE function calculates the percentage growth.

Try using this measure in your Funnel Visual and see if it gives you the desired results.