Power BI using Manage Roles to Return Multiple Selections

Question

I hope I'm just missing something simple but I've had no luck figuring this out so far;

My report needs restricting by who is looking at it, hence using the 'Manage Roles'.

The Clients are A, B and C

There are two Users

Person 1 can access A & B

Person 2 can access A & C

My Table is'ClientRestrictor'

Email	Client_Code
1, 2	A
1	B
2	C

relationship is one to one (ClientRestrictor to Clients)

In manage roles I currently have ;

UserPrincipalName() = [Email]

But this only works to show Client B for User 1 and Client C for User 2

I tried using Find to match without success

Find(UserPrincipalName(), [Email]) > 0

Can anyone suggest how I can have both users able to access client A's data? Thanks

NB: Splitting the first row out result in error when trying to refresh, 'duplicate value is not allowed'