not showing new groups for the existed user

Hi guys,

I am facing small technical issue.

I have created user account for the project A2 under service line X. But user telling that he is not able to see this folder.

This user account (ex: Y) already assigned to another project called A1, When I checked user properties it is showing only old groups, not showing new A2(new one) groups.

But when verified A2 showing list of users with including user account Y account.

here i am not writing project name and service line...

A1: it is folder already user has assigned

A2: it is new one

Y is account name

As of my knoledge recently i am facing this issue.

If we are going to assigning one user for 1 folder, if it is existed, is there any process or procedure in this case?

Please help me to resolve this...