I have created website which has one main portal and many child portals. Also I created one user "user1" which has access of all child portals
To do this I have add user entry in userportal table and assign roles by adding entries in Userroles table.

Main and child portals have same roles but user "user1" has different roles in different portals.

Now issue is that when user is logged in main portal and open any child portal in another tab, user is displaying as logged in user
in child portal but role permission is not applied correctly in child portal. I think this is due to "PortalRoles", etc. cookies sharing

How can we create separate cookies for each child portal and main portal or how can we resolve this issue?

@cathal: Thanks for your reply.

I am using DNN 4.9.0 version. If this version does not support the feature that you are saying then let me know how can I implement this feature in DNN 4.9.0. Currently I am not able to upgrade DNN version.

I can do the changes in DNN core dll if require regarding cookie creation part. Just provide steps/approach to resolve this issue.
Currently when I log-in into the site below cookies are created.
DOTNETNUKE
ASP.NET_SessionId
authentication
language
portalaliasid
portalroles