Row level security _ DAX

hello sturlaws 

Here is a new screenshot, more clear one. 

Thank you for the code, but that's not what I actually need. I also have that part working using this code:

[REGION_ID] IN
distinct(
SELECTCOLUMNS(

FILTER('V_SECU_REGION2',
'V_SECU_REGION2'[USER_ID] = USERPRINCIPALNAME()),

"RegionID" , 'V_SECU_REGION2'[REGION_ID])
)

let's say for instance i have 2 users, then my tables would like this:

V_SECU_REGION2:

Index  USER   RegionID/LB

1        user1    RegionA

2       user2     RegionB

TD_SECU_SECTOR

Index    USER    SectorID

1           user2    SectorB01

When i have my tables set like this, it means that my user1 is supposed to have access to all sectors composing regionA (Sector A1, A2, A3,..)

In my current security, I'm able to apply security for user2 but for user1, I can't manage to show all the sectors. I hope this screenshot will be explain further what i'm looking for:

I thought about doing something like this to put in place security:

IF ( user from V_SECU_REGION exists in both tables; 

     then get sector_ID from table TD_SECU_SECTOR that will filter TD_secotor that will filter my fact table [already works]

    else get sector_ID from TD_SECTOR that will filter my fact table [stuck at this part ] )

For the last part, I wrote this code, thinking in this case, I will be able to get my sector_ID from TD_SECTOR, but it doesn't work.

SectorID = SELECTCOLUMNS(FILTER(TD_SECTOR; TD_SECTOR[REGION_ID] = VALUES(V_SECU_REGION[REGION_ID])); "SectorID" ; TD_SECTOR[SECTOR_ID]))

I hope I managed to explain better my issue,

Regards,

Mariem,

Hello sturlaws 

Here is a more clear screenshot  I actually don't have the regionID in my TD_SECU_SECTOR table however, however, I have added your code to my V_SECU_REGION2 table and it doesn't give me the results I need.

Let's say I have 2 users and 2 regions, each composed of 3 sectors, then my tables would look like this:

V_SECU_REGION2                                                                 TD_SECU_SECTOR 

index   user   regionID                                                     index     user   sectorID

1        user 1    regionA                                                      1       user2    sectorB1

2        user2     regionB                                                       2      user2    sectorB3

It means that my user1 is supposed to see all sectors of regionA, here is more screenshot to explain my current situation

I was thinking about using an IF statement to apply security that behaves in this way:

IF ( user from V_SECU_REGION2 exists in TD_SECU_SECTOR 

    THEN   get sectorID from TD_SECU_SECTOR  which will filter my TD_SECTOR which will filter my fact table

    ELSE get sectorID directly from TD_SECTOR which will filter my fact table [can't get the code to work correctly]  )

I thought of using this code when I have a case like user1 but it doesn't work: