Hi @Sifu ,
Could you tell me:
Do you have a record similar to the picture below?

// 'Test' is a 'Single line of text' column.
Do you want to fill the combo box control with these three emails?
If so, you could use this formula on Items property of combo box control:
ForAll(Split(First(LIST112).Test,";"),TrimEnds(Result))
If you want to get all UserProfiles and fill the combo box control, you could tyr this formula on Items property of combo box control:
ForAll(ForAll(Split(First(LIST112).Test,";"),TrimEnds(Result)),Office365Users.UserProfileV2(Value))
Best Regards,
Wearsky
If my post helps, then please consider Accept it as the solution to help others. Thanks.