Link table data with measures data and display in a visual

I’m working on a Power BI report and need assistance with combining forecasted and actual space data, while ensuring the ability to filter the data by Kostenstelle (department). Below is my data model setup and the approach I’m using:

Data Model:

I have a few key tables in my model:

1. • Kostenstelle (group identifier)
   • Subdepartment
   • Department

     dimNutzerstructure (dimension table containing user categories):

Example entries:

2. ExportRDB (room data):

• RoomID
• Kostenstelle
• Fläche in m² (area)
• DIN277-1 (room type: e.g., NUF2 for office, NUF4 for storage)

Example entries:

3. factPersonaltapete (user data):

• Kostenstelle
• Name
• Department

Example entries:

Measures:

I am using the following measures to calculate space needs for each user category:

1. Bürobedarf (forecasted office space):

Bürobedarf = 
SUMX(
    VALUES('factPersonaltapete'[MA-Kategorie]), 
    [Anzahl Angestellte] * 
    LOOKUPVALUE(
        'Bueroflaechenrichtwerte'[Büro - Richtwert, m²],
        'Bueroflaechenrichtwerte'[Dienstbezeichnung], 
        'factPersonaltapete'[MA-Kategorie]
    )
)

2. Anzahl Angestellte (number of employees):

Anzahl Angestellte = COUNTROWS('factPersonaltapete')

3. Lagerbedarf (forecasted storage space):

Lagerbedarf = [Bürobedarf] * 0.05

To get the actual amount of office and storage space, I calculate the sum of the Fläche in m² column from the ExportRDB table, categorized by the DIN277-1 column (with values NUF2 for office space and NUF4 for storage space).

Approach:

I created a ComparisonTable using UNION to combine forecasted and actual space data:

ComparisonTable = 
UNION(
    ROW("Category", "Office Space", "Forecasted", [Bürobedarf], "Actual", SUMX(FILTER('Export RDB', 'Export RDB'[DIN277-1] = "NUF2"), 'Export RDB'[Raum - Fläche in m²])),
    ROW("Category", "Storage Space", "Forecasted", [Lagerbedarf], "Actual", SUMX(FILTER('Export RDB', 'Export RDB'[DIN277-1]  = "NUF4"),'Export RDB'[Raum - Fläche in m²])),
    ROW("Category", "Laboratory Space", "Forecasted", [Gesamt Laborbedarf], "Actual", SUMX(FILTER('Export RDB', 'Export RDB'[DIN277-1]= "NUF3"), 'Export RDB'[Raum - Fläche in m²])
))

Result

Issue:

I am unable to filter this visual with the Kostenstelle column to display both the used and forecasted space for each department.

Question:

1. Is the approach I’m using reasonable, or am I missing something in my logic?
2. How can I combine the data from these measures with the data from the ExportRDB table, while still enabling filtering by Kostenstelle (department) in my visual?