@FelixZhou, To be able to access the Snapshot copies within the destination SVM of an active SVM-DR relationship you can use -identity-preserve false parameter when you setup your SVM-DR relationship. With this parameter you can start the destination SVM using vserver start <svm-name> command and you should be able to access the R/O DP volumes and their snapshots.
If you want self-service for your users, you will have to do the above and then create a new NAS identity for your users to mount.
Note: this will mean that the source SVM's NAS(NFS/CIFS export policies/shares, etc) and network (IP addresses, etc) configuration information will not be transferred and in the event of a needed failover to the destination, you will have to reconfigure the network settings of the destination SVM to those that were used by the source SVM (or reconfigure your clients...though reconfiguring the destination SVM will probably be simpler and faster 😀)
I am a NetApp employee.