Owin claims - Add multiple ClaimTypes.Role

@Parameswar Rao explained well but in case of dynamic roles

For example a user object already has property role of type list like

then using localfunctions

  ClaimsIdentity getClaimsIdentity()
                {
                    return new ClaimsIdentity(
                        getClaims()
                        );

                   Claim[] getClaims()
                    {
                        List<Claim> claims = new List<Claim>();
                        claims.Add(new Claim(ClaimTypes.Name, user.UserName));
                        foreach (var item in user.Roles)
                        {
                            claims.Add(new Claim(ClaimTypes.Role, item));
                        }
                        return claims.ToArray();
                    }

                }
                    var tokenDescriptor = new SecurityTokenDescriptor
                    {


                        Subject = getClaimsIdentity()
                    }

A claims identity can have multiple claims with the same ClaimType. That will make it possible to use the HasClaim method for checking if a specific user role is present.

var identity = new ClaimsIdentity(new[] {
            new Claim(ClaimTypes.Name, name),
            new Claim(ClaimTypes.Email, email),
            new Claim(ClaimTypes.Role, "User"),
            new Claim(ClaimTypes.Role, "Admin"), 
            new Claim(ClaimTypes.Role,"SuperAdmin")
    },
        "ApplicationCookie");