Compare 2 columns for more than one same matches and return a different column as an output

[Anonymous]

Observation
ID	Question	Observation Type	Observation
123	Q1	Recommendation	O1
123	Q1	Recommendation	O2
123	Q1	Supporting Evidence	O3

Checklist
ID	Question	Observation
123	Q1	O1
123	Q1
123	Q1

Using the below DAX I could return only one observation, Please help to me to return all the values into "Checklist" table from "Observation" table.

Observation = CALCULATE(FIRSTNONBLANK(Observation[Observation],1),filter(ALL(Observation),

                Checklist[ID] = Observation[ID] &&

                Checklist[Question] = Observation[Question]))

[JamesFR06 · Accepted solution]

Hello

Please try this code :

Obs =

var IDP=SELECTEDVALUE(Checklist[ID])

var Q=SELECTEDVALUE(Checklist[Question])

RETURN

CONCATENATEX(filter(Observations,Observations[ID]=IDP&&Observations[Question]=Q),Observations[Observation],",")