Lookup & Concatenate Values in a Matrix

Hi Dilbertfan 

Try the below DAX:

Look Up & Match Use Case (Concatenate Dataset) =

VAR UseCaseRow = SELECTEDVALUE('fctSiPAssets 1'[UseCaseNo])

VAR UseCaseCol = SELECTEDVALUE('fctSiPAssets 2'[UseCaseNo])

-- Get all datasets selected in slicers

VAR SelectedDataset1 = VALUES('fctSiPAssets 1'[Dataset ID])

VAR SelectedDataset2 = VALUES('fctSiPAssets 2'[Dataset ID])

-- Build dataset combinations via CROSSJOIN

VAR AllDatasetCombinations =

ADDCOLUMNS(

CROSSJOIN(

SelectedDataset1,

SelectedDataset2

),

"Dataset1_Alias", [Dataset ID],

"Dataset2_Alias", [Dataset ID] )

-- Filter combinations by UseCase intersection

VAR FilteredCombinations =

ADDCOLUMNS(

AllDatasetCombinations,

"CombinationText",

VAR CurrentDataset1 = [Dataset1_Alias]

VAR CurrentDataset2 = [Dataset2_Alias]

-- Lookup Outcome

VAR OutcomeFound =

LOOKUPVALUE(

'DatasetOutcome'[Outcome],

'DatasetOutcome'[Dataset 1], CurrentDataset1,

'DatasetOutcome'[Dataset 2], CurrentDataset2 )

-- Check if datasets match row and column UseCase

VAR MatchRow =

CALCULATE(

COUNTROWS('fctSiPAssets 1'),

'fctSiPAssets 1'[Dataset ID] = CurrentDataset1,

'fctSiPAssets 1'[UseCaseNo] = UseCaseRow

) > 0

VAR MatchCol =

CALCULATE(

COUNTROWS('fctSiPAssets 2'),

'fctSiPAssets 2'[Dataset ID] = CurrentDataset2,

'fctSiPAssets 2'[UseCaseNo] = UseCaseCol

) > 0

RETURN

IF(MatchRow && MatchCol && NOT ISBLANK(OutcomeFound),

CurrentDataset1 & " & " & CurrentDataset2 & " = " & OutcomeFound,

BLANK() ) )

RETURN

CONCATENATEX( FILTER(FilteredCombinations, NOT ISBLANK([CombinationText])), [CombinationText], UNICHAR(10) )