Building Waterfall Chart Stores Open and Close

Hello community!

I'm trying to build a Waterfall Chart in Power BI to show the monthly evolution of a network of units (e.g., branches or locations), considering:

• In → Units opened during the month

• Out → Units closed during the month

• Total → Total active units at the end of the month.

My Base Table 
I have a table called 'UnitsTable' with the following fields:

Here´s an example of the data: 

UnitID OpeningDate ClosingDate

What I Want to Build

I’d like to generate a Waterfall Chart with three bars per month:

• In → Units opened

• Out → Units closed

• Total → Cumulative total of active units

The previous image is an example of how I want my chart to look — it was created in Excel, but I want to achieve the same output in Power BI.

What I Tried
I tried creating a measure-based approach, but the result was disorganized and hard to control within a visual. So I decided to build a calculated table to better structure the values by category and date.

Waterfall_InOut = 
VAR UniqueDates =
    DISTINCT (
        UNION (
            SELECTCOLUMNS(
                FILTER('UnitsTable', NOT ISBLANK('UnitsTable'[OpeningDate])),
                "Date", DATE(YEAR('UnitsTable'[OpeningDate]), MONTH('UnitsTable'[OpeningDate]), 1)
            ),
            SELECTCOLUMNS(
                FILTER('UnitsTable', NOT ISBLANK('UnitsTable'[ClosingDate])),
                "Date", DATE(YEAR('UnitsTable'[ClosingDate]), MONTH('UnitsTable'[ClosingDate]), 1)
            )
        )
    )

-- Entries
VAR Entries =
    ADDCOLUMNS (
        UniqueDates,
        "Category", "In",
        "Value",
        VAR CurrentDate = [Date]
        RETURN
            CALCULATE (
                COUNTROWS('UnitsTable'),
                FILTER (
                    'UnitsTable',
                    NOT ISBLANK('UnitsTable'[OpeningDate]) &&
                    EOMONTH('UnitsTable'[OpeningDate], 0) = EOMONTH(CurrentDate, 0)
                )
            )
    )

-- Exits
VAR Exits =
    ADDCOLUMNS (
        UniqueDates,
        "Category", "Out",
        "Value",
        VAR CurrentDate = [Date]
        RETURN
            -CALCULATE (
                COUNTROWS('UnitsTable'),
                FILTER (
                    'UnitsTable',
                    NOT ISBLANK('UnitsTable'[ClosingDate]) &&
                    EOMONTH('UnitsTable'[ClosingDate], 0) = EOMONTH(CurrentDate, 0)
                )
            )
    )

-- Totals
VAR Totals =
    ADDCOLUMNS (
        UniqueDates,
        "Category", "Total",
        "Value",
        VAR CurrentDate = [Date]
        RETURN
            CALCULATE (
                COUNTROWS('UnitsTable'),
                'UnitsTable'[OpeningDate] <= EOMONTH(CurrentDate, 0),
                OR (
                    ISBLANK('UnitsTable'[ClosingDate]),
                    'UnitsTable'[ClosingDate] > EOMONTH(CurrentDate, 0)
                )
            )
    )

-- Combine all data
RETURN
    UNION (
        SELECTCOLUMNS(Entries, "Date", [Date], "Category", [Category], "Value", [Value]),
        SELECTCOLUMNS(Exits,   "Date", [Date], "Category", [Category], "Value", [Value]),
        SELECTCOLUMNS(Totals, "Date", [Date], "Category", [Category], "Value", [Value])
    )

Example Result: 

Date Category Value

My Visual Result: 

Let me know if there’s a better way to build the cumulative calculation or if there's a more elegant way to display this in a Waterfall Chart.

Thanks in advance!