Power BI Waterfall Chart Issue with Excluding Item from Breakdown

Hello,

I'm facing an issue with my Waterfall chart in Power BI, specifically when trying to exclude the item "A" from the breakdown. I would greatly appreciate your insights and suggestions on how to resolve this problem.

Here's a brief overview of the issue:

1. Start point: I want to display the Prior Period  value for the item "A" in the Waterfall chart.
2. End point: I also want to display the Current Period  value for the item "B" as the end point in the Waterfall chart.
3. Between: For the items other than "A", I want to display the Variance  value in the Waterfall chart.

I've tried using various DAX expressions, including the SWITCH function and conditional statements, but I haven't been successful in achieving the desired outcome. When I try to exclude the "A" item from the breakdown, the chart ends up being empty.

Here's the DAX expression I'm currently using:

walk = 
VAR walkitem = SELECTEDVALUE(Walk[Value])
RETURN
    SWITCH(
        walkitem,
        "CY", CALCULATE([Current], [LEVEL2] = "A"),
        "PY", IF(COUNTROWS(FILTER(VALUES([LEVEL2]), [LEVEL2] <> "A")) = 1, -[Variance], CALCULATE([Prior], [LEVEL2] = "A")),
        BLANK()
    )

 But unfortunately I still see A as breakdown, for example