Dropdown list in slicer

Yes, absolutely possible in Power BI. Below I give a clear, working approach (step-by-step) plus the exact DAX you can drop into your model. The idea: make a small Week table (with a numeric week column), use two single-select slicers from that table as From Week and To Week, and then create measures that (1) apply the chosen range and (2) validate that To > From. Project_ID and Phase_ID slicers will naturally limit the weeks shown if you build the relationship as described.

1) Create a Week table (calculated table)

Use this calculated table in Modeling → New table:

WeekTable =

VAR w =

    ADDCOLUMNS(

        DISTINCT ( V_ABC[Phase_Week] ),

        "WeekNum",

            VALUE (

                SUBSTITUTE( TRIM( [Phase_Week] ), "Week ", "" )

            )

    )

RETURN

SELECTCOLUMNS( w, "Phase_Week", [Phase_Week], "WeekNum", [WeekNum] )

Notes:

• This extracts WeekNum from strings like "Week 1". Adjust the SUBSTITUTE if your labels differ.
• WeekTable[Phase_Week] will be used for the slicer labels, and WeekNum is numeric for comparisons.

2) Create a relationship

Make a relationship in the model:

• WeekTable[WeekNum] (one) → V_ABC[WeekNum] (many).

If V_ABC does not yet have a numeric WeekNum, add a calculated column there:

V_ABC_WeekNum =

VALUE( SUBSTITUTE( TRIM( V_ABC[Phase_Week] ), "Week ", "" ) )

Then relate WeekTable[WeekNum] → V_ABC[V_ABC_WeekNum].

This relationship enables the Project_ID and Phase_ID slicers (on fields from V_ABC) to cross-filter the WeekTable, displaying only weeks relevant to the selected project/phase.

3) Add slicers to the report

• Add slicer for V_ABC[Project_ID] (multi or single select as you want).
• Add slicer for V_ABC[Phase_ID].
• Add two slicers for the week using WeekTable[Phase_Week]:
  • Label one slicer "From Week"
  • Label the other "To Week"
  • Set both week slicers to Single select (so the user picks one value each).

Because of the relationship, when you select a Project and Phase, the week slicers will show only weeks available for that project/phase.

4) Selected week measures

Create these helper measures:

SelectedFromWeekNum :=

SELECTEDVALUE( WeekTable[WeekNum] )

SelectedToWeekNum :=

SELECTEDVALUE( WeekTable[WeekNum] )

(You can place them in a card during testing to see values; they return blank if nothing is selected.)

5) Validation measure (To must be > From)

Create a validation measure to show whether the selection is valid:

IsWeekRangeValid :=

VAR f = [SelectedFromWeekNum]

VAR t = [SelectedToWeekNum]

RETURN

IF(

    OR( ISBLANK(f), ISBLANK(t) ),

    BLANK(),            // no message until both selected

    IF( t > f, 1, 0 )

)

You can show this as a Card or use it in conditional formatting. 1 = valid, 0 = invalid.

Or an explanatory text measure for users:

WeekRangeMessage :=

VAR f = [SelectedFromWeekNum]

VAR t = [SelectedToWeekNum]

RETURN

IF(

    OR( ISBLANK(f), ISBLANK(t) ),

    "Please select From and To weeks.",

    IF( t <= f, "Error: To Week must be greater than From Week.", "" )

)

Put WeekRangeMessage in a Card so users get immediate feedback.

6) Main measure that restricts data to the selected range

Example: count rows (or compute other metrics) in the selected week range and respecting Project_ID & Phase_ID slicers:

RowsInSelectedWeekRange :=

VAR f = [SelectedFromWeekNum]

VAR t = [SelectedToWeekNum]

RETURN

IF(

    OR( ISBLANK(f), ISBLANK(t) ),

    BLANK(),                        // or 0 if you prefer

    IF(

        t <= f,

        BLANK(),                    // invalid selection -> blank (won't plot)

        CALCULATE(

            COUNTROWS( V_ABC ),

            FILTER(

                V_ABC,

                V_ABC[V_ABC_WeekNum] >= f

                && V_ABC[V_ABC_WeekNum] <= t

            )

        )

    )

)

Important: I did not remove filters in CALCULATE, so this result will still honor Project_ID and Phase_ID slicers. If you do want to ignore Project/Phase filters, wrap the V_ABC table with ALL(V_ABC) inside FILTER.

7) UX tips/enforcement

• Power BI slicers themselves cannot force “To > From” (you can’t block a bad selection directly inside the slicer). Instead:
  • Use the WeekRangeMessage card to show an error message when the user picks an invalid range.
  • Use your measures to return BLANK() (or 0) when selection is invalid so charts/tables show nothing (or an alternate visualization prompting correction).
• Make both week slicers single select — this simplifies the logic.
• Optionally add a bookmark or a button wired to a measure/bookmark to clear selections (if you want a “Reset weeks” control).
• If your Phase_Week values are not always formatted as "Week N", adapt the parsing logic accordingly.

Example flow for the user

1. User filters Project_ID and Phase_ID (optional).
2. The From & To Week slicers show only weeks that exist for that project/phase.
3. User picks From and To (single values). If To ≤ From:

• WeekRangeMessage card warns: “To Week must be greater than From Week.”
• Main visuals return BLANK (or show 0) until corrected.

1. If valid, your visuals (table/chart counts, etc.) display results for rows where WeekNum is between From and To and also match selected Project/Phase.

If you found this post helpful, please consider accepting it as the solution so that other members can find it more easily.

Regards,

Khashayar Yazdani | Microsoft MCT

https://www.linkedin.com/in/khashayary/